Sister in law to be.

We told the family today. :-) everyone is so happy except his sister in law. She has tried and tried for years. She has two girls 9&7. She so desperately wants a boy. Well when we told everybody she got mad and she pitches a fit in with my fiancé sisters, she told them to tell her first if she can mentally prepare for it. I don't need to do with it and I don't know how to go around or even talk to her. She hid for two hours pitching a fit and crying :-(