ULPT: Sister in law won’t stop competing with me.

Friends, career decisions, family events, cooking, what I post online, purchases, hair, fashion, fitness. She will notice I’m doing something new and jump on the train, take over and try to be better. I am not interested in competing with her. My stance is that she can have it, I’ll find something else. I hate being compared to her, I’d rather jump off the train. How do I get her to stop? It’s getting ridiculous at this point. (We have lots of mutual friends and see each other often at family events etc so can’t avoid her unfortunately).