Disclaimer - still don't own Hawaii Five-0. Still just toying with their lives for a while. I googled Mrs. McGarrett's name and the only thing I found was one thing that said Doris. But I didn't find anything to necessarily back that up. I'm gonna go with it, even though I'm not 100% sure.
Spoiler - "Ua Hala", Season 2 Finale
His heart was racing as he stared at the door before him. Racing much faster than he knew was good for his body. Joe had brought him here, to a tiny village in Japan, to meet the elusive Shelburne. Names, faces from his past sped through his mind, but nothing could have prepared him for the face he saw… "Mom?"
Doris McGarrett was thinner than Steve remembered. Her once lustrous brown locks had grayed, calling even more attention to the greenish blue eyes she shared with her son. "Hello, Steven," she said softly, opening the door fully and stepping aside, encouraging him to cross the threshold into the home. He willed his body to move, to take his mother into his arms, to hold her, to feel the heat from her body, to feel her heart beating in her chest. But his body would not obey, choosing instead to remain frozen on the small porch. "How…" he stuttered, blinking in quick succession. "How? What? I…"
The older woman smiled gently at her son. "There is so much I need to tell you, Steven. Please come in."
Steve looked over his shoulder again, hoping that Joe had re-appeared just as magically as he'd disappeared a few moments earlier. He took a deep breath and closed his eyes before turning back to his mother, fully anticipating that seeing her, alive, before him had been little more than a mirage. When he opened his eyes again, the matching pair opposite his were warm and inviting. Once again, he willed his body to move, startling himself as he finally crossed into the house. Doris shut the door behind him and waved a hand toward a small settee in the middle of the room. Steve sat, watching intently as his mother eased down next to him. She reached one hand out to him and asked "May I?"
Steve nod his head slowly, allowing her to take his left hand in hers. He studied their joined hands, his so much larger than hers. Her skin was thinner than he remembered, finding blue veins pulsing prominently below the surface. He sucked in a breath as he noticed her bare ring finger. He didn't know why, but it never occurred to him that his mother wouldn't be wearing her wedding rings. Complete, utter shock was slowly giving way to anger as he heard his voice demand, "YOU are Shelburne?"
"Yes," she answered plainly.
Steve shook his head in a desperate attempt to clear the fog that had settled since his mother opened the door. "You let Mary and I believe…" he said incredulously.
"Yes," she replied again.
His brow furrowed in confusion. All his mother had offered him was a one word explanation. "Why?"
A burst of angry sadness flashed in her eyes before she answered, "To protect you."
"To protect me?" Steve repeated slowly.
She squeezed his hand gently. "Doris McGarrett did die 21 years ago, Steven. I was not Doris before I met your father, and I have not been Doris since the day she died."
"I don't…" he began quietly, his eyes searching hers for more answers. "I don't understand."
"I was born Nancy Sheldon in Washington, D.C. in 1946 to Commander Thomas and Mary Sheldon. My father was a Navy pilot stationed at Pearl Harbor in 1941. He was stateside on December 7, 1941 because his father, my grandfather had died 5 days prior. He returned to Pearl to find most of his friends had been killed. After the war, he was recruited by one of his commanding officers into the Central Intelligence Group…"
"Precursor to the CIA," Steve added with another disbelieving shake of his head.
"Yes," Doris answered.
"So, what, you followed his lead into the CIA?" Steve surmised aloud.
She nodded affirmatively. "I was recruited my senior year at Georgetown. I'd suspected my father was CIA, but never had any confirmation. By the time I was old enough to really pay attention to his comings and goings, he was senior enough to be in the main office most of the time. I wanted desperately to do this, to be a part of protecting my country, just like my father. Three weeks after I graduated, my parents were killed when the small plane my father was piloting crashed on the way to our summer house in the Outer Banks of North Carolina. All I was told was that the plane experienced a malfunction and crashed. No explanation as to why an experienced aviator with hundreds of flight hours under his belt didn't, at the very least, radio that the plane was malfunctioning. It wasn't until I'd been in the agency for three years that I had the clearance to access the files associated with the crash…"
"That's all fascinating, Mom, but how did you become Shelburne?" Steve demanded, his patience wearing thin.
"What I discovered in the files led me to believe that my parents were killed because of an investigation my father was conducting into the Yamaguchi-gumi family."
"The Yakuza," Steve interjected.
"Which, at the time, was run by your pal Wo Fat's grandfather, father and uncle," she explained. "In 1973, I was assigned to Hawaii and tasked with intercepting several low-level Yamaguchi-gumi the agency believed were attempting to arm themselves with nuclear weapons. In July of 1974, a team of SEALs led by Joe killed 5 family members in the middle of an arms buy from a high ranking army officer who had gone rogue. Wo Fat's father was among the 5 killed. All documentation regarding the investigations in Hawaii were entered under the name Shelburne. The CIA has…dealt…with the agents who were instrumental in providing the Yamaguchi-gumi family with information about the SEALs mission and Shelburne."
Steve shifted uncomfortably on the settee as he processed all the information his mother had given him. He knew it was only the tip of the proverbial iceberg though. He had so many more questions about how she met his father, where Joe came into the picture with his parents beyond being an unnamed SEAL commander. As if she could read his mind, Doris spoke again. "I know you have more questions Steven, and I will answer every one of them. But, you need to know I'm not here alone."
Steve shrugged his shoulders. "Yeah, Joe's been here, I know that already."
"Not Joe," Doris replied with a shake of her head.
"Then who?" Steve asked angrily. "Who else from my past is going to pop up and say hello, Mom?"
"Me," a female voice answered clearly from the opposite corner of the room. Steve's head whipped around to face the voice. The identity of the woman before him was almost as shocking as finding his dead mother alive. His heart caught in his throat as he struggled to answer.