The following changes nothing regarding this trial, but I had a wild thought ....
Maybe she really did not realize she was pregnant. She had erratic periods (likely due to eating disorder) and some sort of bleeding or spotting during the pregnancy if I remember correctly. It was late in the pregnancy when she found out. And the baby was not Brandon’s, her current boyfriend. Not only would she have to face her parents, Brandon would also learn and may leave her. So she was putting off confronting anyone, including herself. Blocked it out as best she could.
All just a hypothetical, of course, and I have no way to know if any is likely.