Maxine

"Maxine" is the baby Vivian Carlsmith was forced to give up for adoption.

History
When Vivian was 15, she gave birth to a baby she was forced by her mother to give up. When Vivian was dying of gastric cancer, she asked Addison to find the baby she'd given up and give her a letter, talking about how she had thought about her every second for the rest of her life.

Addison found her and sat with her as she read the letter.

Familial
After she was adopted, she had a full life with a big Catholic family.

Notes and Trivia

 * As Vivian didn't raise her and therefore didn't name her, it's unlikely Maxine is really her name.