Should I confront my Mom?

I think you have the right to take a part on that responsibility, anyway, it is your own nephew not somebody else. Talk to your mom sincerely but watch your tone and choose the right words. our mothers sometimes think that we are disrespectful when they heard a word not pleasant for them. also, think about the right time to talk to your mother. a good mood makes a good result. well then, god bless and good luck.