Can I make a girl do a TIKTOK warmup in PE?
That depends. How do you plan on having her do a TIKTOK warm up in PE?
I will persuade her to.
Its good that you are having her warm up before participating in gym. Not completely sure what a TIKTOK warm up would be, however any warm up is better than no warm up.
I will help her out but pushing her out of her comfort zone, she is too scared to do this by herself.
You are amazing for wanting to help her out that way. You deserve praise and  hopefully she will be a success with her sports in PE gym class.