terrible at saying no?

I have a friend who’s The Go-To. Everyone calls her when they need something. And for a long time she loved being that person (aka the reliable helper) Then one day she realized she deeply resented it, but she couldn't figure out how to stop because she'd built an identity around always saying yes. Saying NO felt… rude. But she hated conflict and worried what people would think about her if she said no… so her solution was just to avoid people… which I suppose is one way to deal with it 😅 But...