My mom has convinced herself

That she knows what I'm having and she's already calling the baby a girl.. But I'm actually having a boy. I'm the only one who knows and everyone's been trying to figure out what I'm having.. But my mom is just dead set that I'm having a little princess. I'm planning to do the gender reveal October 4 for our families.. I'm biting my tongue every time she says "oh she's getting so big" or "I have to get this for her room" lol