She should look on the bright side. Just because her baby is a boy sexually doesn't mean he'll automatically identify as one. She could still have a child whose gender is female.
Love it! The missuse of sex vs gender is a pet peeve.
Also, if my family was SO insistent that they wanted a boy or a girl, I'd junk punch them. What a douchey thing to do. My dad has already says he wants a grandson at some point because his girlfriend has 3 granddaughters and I said, "welp, not something I can control or care about that much."