

I’ve been abused (physically and mentally) by my parents and bullied at school. I can obviously only talk about myself, but maybe my experience helps you.
Understanding, that those people will never care or feel guilt, is hard. Especially when you were abused as a child and hoped for a happy end. Actively trying to get over it also didn’t work very well for me. For me the best thing to do was focus on other things: find friends, find hobbies, do whatever you always wanted to do (I started wearing clothes I was forbidden to wear and practicing hobbies that were ridiculed).
Just fill your life with things you like and the bullies and abusers will become smaller and smaller.
Therapy is a good start to help you with this and question yourself, who you are and who you want to be.
Just keep telling her she’s awesome. Don’t focus on the legs, just tell her all the things you love about her. And if she directly asks you about them, don’t make it a big deal. Just say “I don’t care, you’re beautiful.” For me the best thing my husband did was to counter the constant onslaught of beauty standards over media by telling me every day what he loves about me and how cool he thinks I am.