@Seeking Pam - They won’t be paying 140k a year…the younger sibling isn’t in college yet. And as for affordability, the family didn’t apply for FA and the OP has stated that money isn’t an object and they were prepared to pay sticker price, so apparently they can afford it.
FWIW - I don’t think the OP wants to withdraw her ED. I think she was just worried about her Mom’s new job. She’s disappeared so maybe she has talked to her parents (something she should have done in the first place) and found out that it isn’t an issue. Perhaps it is time to move on as well.