Edited for Vera-Thanks for reminding me UncleCatwoman! I had her planned and forgot to put her in.
It would be easy to say that they lived happily ever after, and so they did. Of course they did in their own Penny/Sheldony way.
When they had been dating for about six months, they went to Texas for the promised visit with Meemaw. Penny stayed with Meemaw, and Sheldon stayed with his Mom. Mary Cooper was still, six months later, trying to wrap her head around the idea that her Snickerdoodle had an actual girlfriend. Not a girl who was a friend, but a 'girlfriend' with kissing and probably sinning. Mary was so happy that he'd found a girl, that she didn't even press on that particular issue. She played the 'don't ask, don't tell' game, and it worked. And if she had her prayer group praying that Shelly would ask that girl to marry him, well, what he didn't know wouldn't hurt him.
Sheldon stood in his Meemaw's kitchen, and overwhelmed with memories of the only place he'd ever been truly happy (before Penny) asked her "officially" to marry him. Since Penny was up to her elbows in suds (they were washing up after dinner), she shot him an exasperated look. "You're the only man I know who finds cleaning up romantic. Whackadoodle." Her expression softened. "Of course, I will you idiot." Seeing the joy and satisfaction on his face brought tears to her eyes. "I do want to wait until I get my degree, though." She cautioned.
"You know it doesn't matter to me, Penny."
"I know, Honey, but it does to me."
"If that will make you happy, then I will, of course, wait."
When Meemaw came in the kitchen to see what was taking so long, she found the two locked in an embrace. "Meemaw, Penny has consented to marry me."
Meemaw's whoop of joy brought Mary and Missy running. Once the news was shared, Mary started planning a celebration party. At the party, Penny realized just how far she'd come. Sheldon's brother, George, big handsome strapping football player type is trying to talk to her and all she could think of was finding Sheldon, so she'd have a decent conversation. And kisses. George saw the dopey smile on her face and excused himself. He didn't know how his brother got so damned lucky, but that girl was obviously crazy about Sheldon.
They drove to Nebraska for Sheldon to meet Penny's family. He was cool to Wyatt, who had continued to nag Penny about her choices, but Penny's mother, Charlene, was almost as in love with Sheldon as Penny was. Unsurprisingly, as Penny told her Mom a lot of stuff that a girl would never tell their dad. Stuff about Leonard and juicy stuff about Sheldon.
When they announced that they were getting married, Wyatt went still and quiet, but Charlene was thrilled, hugging Penny and Sheldon, who suffered through it gracefully.
"You know, dad, you can be happy for me, for us, or not, but either way, this is going to happen. Do you want me to ask Uncle Pete to give me away?"
That brought Wyatt up short; he'd only ever wanted her to be happy and safe. "No, baby, I am happy for you. For you both."
"I promise Mr. Olson, Penny and I will never live in a mobile home."
"Yeah, dad. Sheldon grew up in one, and feels pretty much the same way you do about them. And when he wins the Nobel, we'll use part of the prize money for a down payment on a house."
"I have it all planned out, Sweetie."
"We have marriage guidelines? Excellent, when may I see them?"
"Once we get home, Sheldon."
Wyatt looked back a forth between his daughter and the nerd she loved. And there was no doubt that Penny loved him, she had the same look on her face that his own Charlene had so many years ago. Wyatt felt a giant weight lift from his shoulders. "You know, Sheldon, you can call me Wyatt. Or Dad. Whichever you're more comfortable with." He offered.
Sheldon blinked at him, shot Penny a look, and said, "thank you…, Dad."
Penny's parents insisted on throwing a small family party for them, and Sheldon met Penny's brother, sister, nephew, and Uncle Pete.
They got married in Pasadena a week after Penny graduated college. Her parents came up for the graduation and stayed for the week. Her mom had planned a pretty sizable wedding for them, although left to their own devices, Penny and Sheldon would have had a quiet elopement.
Leonard was best man, and Missy was maid-of-honor. For their honeymoon, the guys had pitched in and got them an Amtrak tour across the country. Sheldon was thrilled, and so was Penny was she found out how many cool places they'd be stopping and that they'd end up in New York. Sheldon promised to take her to a Broadway play. They both enjoyed it very much, and were quite grateful to the guys.
Once Penny convinced Sheldon that since he was the Alpha-Nerd he had a responsibility to his sidekicks (minions), he took his noblese oblige very seriously. Especially once Penny pointed out that they and their behavior reflected on him. He convinced Howard to get his Doctorate, stating that he wouldn't want Bernadette to have one and him not. Sheldon helped Raj secure a permanent position with Caltech, and finagled Leonard into working on some more original experiments. And they all prospered.
Sheldon always tried to adhere to Penny's marriage guidelines, as the dating ones had worked out so well. One area they did almost fail in. Penny thought that they should wait until Sheldon won his Nobel to start having babies (much to the chagrin of Mary Cooper, Charlene Olson, and Meemaw). However, when they'd been married a little over a year, Penny discovered that 99.9% effective was not the same as 100% effective. In short they were pregnant.
"You listen to me, Sheldon Cooper; you better get the lead out and win that Nobel. Once this baby comes, you won't have the time."
"But, Penny, what about the prenatal classes and doctor visits?"
"Covered. Meemaw's coming to help, and the guys will, too. You focus. We are not going off the guidelines now. You're going to want to spend time with us once this one's born, so hop to it."
So Sheldon put his nose to the proverbial grindstone and by the time Penny was 7 1/2 months pregnant, had made the breakthrough that would eventually prove string theory. Meemaw helped Penny keep Sheldon fed and focused, and the guys helped with the classes and doctors' visits.
It was during one of the doctors' visits that Leonard ran into Stephanie and they remembered how much they liked each other. They eventually got married and Leonard ended up surrounded by women who adored him, as they had 4 daughters. He was hugged frequently.
Howard and Bernadette had the most bizarre wedding that any of the gang had ever been to. They were married by a Catholic Priest (for Bernadette's mother) a Rabbi (for Howard's mother) and had Hindu undertones (for Best man Raj). They lived with Howard's Mom, and trundled along quite happily. They had two daughters, who Howard watched like a hawk. No one knew better than him what kind of animals men are.
Raj hooked back up with Lalita Gupta, who realized that he was a lot nicer than she had first thought (Penny made him a short set of guidelines, which he followed religiously; they worked for Sheldon, after all).They had two very handsome sons, who had no trouble talking to women.
Missy Cooper ended up married to a very successful actor from Texas, and they had a set of twins; a girl and a boy.
Amy Farrah Fowler had a tempestuous on again off again affair with Zach and they had a son. They never got married, but they maintained the relationship far longer than many marriages last.
Vera did indeed graduate both high school and college, and she became a Math Professor and married a tall, blue-eyed Physics Professor. Probably just a coincidence.
Sheldon was awarded his first Nobel just after the birth of their first son, Lee Sheldon. He won his second mostly by accident after the twins: Stephen Jacob and Sarah Jane were in college, almost 25 years later. Penny never did catch that "Big Break", but was quite content as a child psychologist, who helped many troubled youngsters.
Their second son, Wyatt George was the only one of their offspring to test off the scales on the IQ test, although all four of the children scored higher than average. Wyatt eventually won his own Nobel for Chemistry. Lee was a very successful contract lawyer, often taking pro bono cases. Stephen became a very famous chef, and had several cooking shows on concurrently. He took up the banner for feeding hungry children, and made great strides for that cause. Sarah Jane went into politics and while she didn't end up ruling the world, she did end up President of the United States and she won the Nobel Prize for Peace.
Sheldon's acknowledgements in his book: "To my wife of 40 years Penny Cooper, a far Nobler prize than the two I claimed in Geneva, our four exceptional children: Lee, Wyatt, and the twins Stephen and Sarah Jane. I probably could have done it without you, but it would not have meant anything without all of you."
A/N I hope it didn't end too sappy for you, and that you've enjoyed reading it even half as much as I've enjoyed writing it. Thank you to all who have read and reviewed.