“Maybe the child she was carrying was her boyfriend’s, and he told her he didn’t want to pay child support”
Unlikely. Oh, the child may have been fathered by a boyfriend, but women rarely kill their children over lack of financial child support. The way she did it shows she was trying to hide the pregnancy in the first place. She was probably thought of as the perfect girl - pretty, a cheerleader, nice affluent family, good grades - and she thought she had ruined everything by getting pregnant. She felt compelled to hide it. And most likely there was no longstanding boyfriend. In most of these cases there isn’t.
But insecure girls who murder their babies sometimes do it in the hopes of keeping the love of the male that impregnated them.