I masterbate regularly and also have a very active sex life. Maybe she does do it, but is just to embarrased to do it in front of you.
My husband was great at the charm and we often use sex toys now, but in the beginning of our relationship I was a little embarrased at first. maybe you don't make her feel comfortable enough and may pressure her.
Think about what you are saying to her and how you are putting it across to her.
