Samantha's secret

This is my first SATC Fanfic. The plot is Samantha had twins twenty two years ago. No one knows about this, not even her closest friends. But what happens when they both turn up in the city looking for her?
Please read and review. Hope you like it. The storyline came to me and half past two this morning- so see what you guys think.

Samantha Jones was a successful business woman. She had earned her right to be at the top of her game, and she wasn't getting off anytime soon. But what no one knew about Samantha was her harboured secret. Not even her three best friends. She tried not to think about it, but it was always in the back of her mind.
It had happened twenty two years ago. She was in her early thirties and starting in her career. As many people who knew Samantha knew that a marital life was not the life that Samantha wanted, certainly being a Mother wasn't on her 'List' either. But that's exactly what had happened. She had kept it a secret from all her friends and colleges, and had took a four month vacation- where she had given birth to her twins and had given them to a couple who were in there last hopes of having children. Samantha signed the papers and had given the couple a check to help them raise the twins. The couple were extremely grateful of Samantha's generosity and had promised her that they would love and look after her children as their own.
Samantha came back from her four month break as if everything was normal. She made up stories of elicit affairs and all the sights she saw just to cover up the real reason for her absence. She didn't know why she hadn't told anyone about her babies or why she felt ashamed by it all, but that was probably down to the father and the fact that Samantha wasn't cut out for parenthood.
She gazed out of her office window and took in the breathtaking Manhattan view. She decided that this evening, when the girls were going out for a little meal in the city and then back to Carrie's for a few drinks, that she would tell them. She didn't know exactly how to start the revelation. It wasn't something you could just spit out over dinner; it was a complex and private thing that she would have to reveal in the sanctuary of a private place. She finally decided that after a few glasses of wine and a nice expensive meal, she would tell the girls once they had arrived at Carrie's.
It was weird because she didn't know why out of the last twenty two years that she had suddenly thought about them constantly over the last few days. But her thoughts were answered when she stepped up from her chair and met the gaze of two familiar eyes. She hadn't seen them since they were barely days old, but she could remember those eyes from anywhere. There standing in her office door way was her grown up children. Her son stood tall, his muscular form visible from his tight fitting t-shirt, and his fashion sense apparent by his choice of outfit. And beside him stood a beautiful blonde, she too was of a healthy build. She was a slender shape, and was wearing a beautiful summer dress. Samantha took in the pairs exterior and felt like she was looking in the mirror.
"I'm Zac and this is my sister Jess, are you Samantha Jones?" he asked…