If I gain weight will it force my mom to stop buying me kids clothes!?

I'm skinny and she buys me little kids clothes. EVENTHOUGH I CAN fit juniors. I have hips and a booty so it's not like I'm just a stick. But maybe if I gained so much that I couldn't fit kids then she will HAVE to buy more mature clothes right? lol. And yes I've tried talking to her about it and she says "Your the child, I'm the adult" I'm not in my preteens btw, I'm in my older teens!