Pain during sex from pubic bone

Interesting one - I've started seeing a lovely girl, but during sex, when facing each other, I think her pubic bone is not aligning properly and so its rubbing into my upper pubic area, really hurts. She is particularly thin and so this maybe the issue, but it is most likely getting the angle of attack right too... but I suppose I wanted to know if this was common, aside from alignment, is there some yoga moves we could practise to improve our sex life?