Can I still show my horse with scars?

She was rescued and her previous owner was abusive. She's a quarter horse with scars all over her (white) back legs and a large scar on her hindquarters that shows up when she sweats. I have been working on her with jumping and I would like to be able to show her eventually but I have been told that you can't show an "imperfect horse." She is sound for all work, just a little marked up.