I love the simplicity of the heels and the tattoo. I think tattoos add something unique to each person, even if it is something as simple as a heart. The heel and foot tattoo combination is cute and I love it.
Well there are a couple of possibilities. The first, one can translate it just as you asked: fortitudo e dolore venit "strength comes from/out of pain" But if you want to simplify it, one can just use: fortitudo per dolorem "Strength through pain"