Gianna Jessen claims she met her biological mother. Some woman came over to her at one of her appearances and said to her, in a Darth Vader voice, "Gianna, I am your mother!" then went into a wild, crazed screechy rant. Gianna was so shocked that all she could do was whisper, "I forgive you, I forgive you."
I don't believe this woman was even her real birth mother. I think she was just some random Code Pink type who wanted to make a scene.