Guys, a lil help..?

So basically, I’ve dealt with a kid for almost my entire life, doing the same stuff I do, randomly having the same hobbies as I do, and more. I cant really do anything about it, but for context, I’ve been making dragon puppets ever since 4th grade, and yesterday, the kid came over, and demanded for me to make a dragon puppet, i told her that it takes a while, and she got mad. Never ever since yesterday did she have ANY interest in the dragon puppet community. And when I said, how about let’s make a design first? She tried to copy one of my dragon puppets. She made her own, and ik everyone’s first one looks crappy, (trust me, my first was a lopsided box with eyes) it looked like a copy of my space dragon, stellar. She’s planning on making a channel, and I explained to her, at her age she shouldn’t have a channel, (bc the age restriction for using YT is 13 anyway,) and that its not the best time for it, because it’s the end of winter break, and our school curriculum goes hella fast now, and she told me to mind my own business, I also explained to her that what she’s doing will leave a long lasting imprint into who she gets interpreted as a person. I explained to her that she can’t just “make her own dragons” and then post them, once every, idk..eternity ? Im against her making a channel bc one, she’s underage, 2, hate, 3, how cooked she is when it comes to comparison, (don’t come for me there) 4, the lasting impact it leaves on a kid like her, 5, the fact that she never showed interest until yesterday, and 6, the amount of times she’s done the same things as me, and the fact it doesn’t feel like a coincidence now. I know I sound really possessive over the hobby, but she’s ruined a bunch of other hobbies that I now hate because of her, and I found a hobby that was unique to me, and then she may go and possibly ruin my love for the community.