In the novel A Tree grows in Brooklyn what is the major challenge that the main character faces?

Francie faces many challenges throughout the book, but a main one is the fact that she is poor. they had hardly any money at all, and what they had was put to the basic necessities.

some side struggles could be that she doesn't have a great father figure in her life, her mom favored her brother over her and was emotionally detached from francie. she also didn't have too many friends, so she wasn't a very social person