Psychiatrist Gail Saltz, author of "Anatomy of a Secret Life: The Psychology of Living a Lie," described the impact such a loss could have on a young girl.
"Losing her father at an early age puts someone a risk," Saltz told ABC News. "It's abandonment, a very frightening one ... and then, of course, be[ing] essentially abandoned by your mother in the setting of her using drugs, that's sort of a double whammy because that is losing the most important person in your life. ... Hard to not internalize that as a tremendous rejection, ... [a] blow to self-esteem and questions of how loveable am I if my mother ... is no longer taking care of me."
Christine's suffering didn't end there. By the time she was in kindergarten, she was diagnosed with an irreversible hair-loss condition called alopecia.
"She would wake up in the morning and there would be clumps of hair all over her pillow, patches here, patches there," Paolilla said. "And eventually led to where it affected her eyes so she lost her eyebrows, she lost her eyelashes."
As a young child, Christine wore wigs to hide her affliction from the world.
"That was devastating," said Paolilla. "She had poor vision so she had what I guess most folks would know as Coke-bottle glasses, and [she] started being ridiculed by young children. ... Classmates would come up behind her, pull her wig off her head.
"It was so painful to watch. I can't even imagine really, truly how she was feeling. As a parent, as a mother the pain of a child, waking up in the morning thinking, 'What am I going to have to go through today? Who is going to hurt me today?' It was very difficult for her."
Saltz said the hair loss would have been a major psychological obstacle.
"Psychologically, to a young person, this is going to take a huge toll," Saltz said. "Hair is hugely important to girls, to women, it's a symbol of femininity, it's a symbol of feminine power ... alopecia is a pretty devastating condition."
Christine's early teen years were a struggle. But eventually she was able to forge new friendships that helped her feel like she belonged.
Lori Paolilla recalled her daughter's joy at having made new high school friends.
"'Mom,' she said, 'I made two new friends who are the sweetest girls I ever met,'" Paolilla said. "I said 'who are they?' She said, 'Rachael and Tiffany.' ... She couldn't speak highly enough about them. How much fun they were. How loving they were, how they had so much fun ... Every minute they spent together was lively and fun, and they laughed all the time and I saw such a change in her personality."
Tiffany and Rachael were a year ahead of Christine in school. "She genuinely seemed very happy when she started to hang around with those girls," said Paolilla.
Rachael was beautiful and popular and may have helped Christine feel like a normal teenager. The intensity of the relationship was understandable, said Saltz. "That relationship would be extra important, full of longings," she said.
Rachael's father wasn't surprised she took Christine under her wing.
"Rachael was the kind of person that always looked out for the underdog, always tried to help others," George Koloroutis told ABC News. "And because of this affliction that Paolilla had ... Rachael really felt sorry for her."