OK PDW,
From a personal point of view I recently started seeing someone and I have issues with my body, so I totally understand where she is coming from. What may seem minor flaws to the other person can be a major hurdle to us girls.
Initially the lights were off and that was a huge hurdle out of the way, take it slowly and she will gradually learn to trust you and realise that this scar is part of what makes her the person you care about.
A bit like my wobbly belly, small boobs and smelly feet!! And a bit like my partners small, yet perfect belly, his nicely receeding hairline and the monobrow which frames his beautiful eyes. It is all relative to the person.
You may not need to say anything, but if you do just let her know that you like everything about her because that is who she is.
Good luck and it does get easier and better!!! ;-)