my mom is in gender denial....

The other day I found out I'm having a girl! It was surprising to blame because boys run in both sides of mine & my husbands family but my family has more girls. I wanted a boy so I tricked my mind into think boy even tho since day one I knew it was a girl! So I was super stoked I get to have spoil my little girl & I called my mom "mom im having a girl! Not a boy like I thought" oh man.... she was pissed! Like what? She kept telling me I was wrong, the ultrasound tech doesn't know what she's doing, she doesn't want to buy girl stuff, she wants a boy, blah blah. Won't quit calling her a he which irritates me most! & im just like wtf? Lmao for one it's not even your baby, two, you're more mad then I am?! I don't know what to do to get her to quit. She won't quit saying "at your next scan it'll be a boy".... ugh she stresses me out lol anybody else deal with this??