It’s not flattering at all when someone copies your hard work. You might want to have a gentle but clear talk with your friend. Let her know that while you appreciate that she likes your style, you’d really prefer if she found her own ideas. You could suggest she look up some
interior design trends to get inspiration that fits her own taste.
Also, try to stop sharing the details of your design choices. If she asks, just give a vague answer or tell her to check out some trends online.