Ridicule
It did not take Brianna long to realize that others would be constantly judging and criticizing her. Due to the way her baby looked, she felt bad about being a mother.
While she was out, people whispered about her baby to her, and she overheard them saying hurtful things about her. The events that led to her death were known to a few people.
The lightning strike might have caused some kind of birth defect in her baby.