One very symbolic tattoo that you may consider is the pink ribbon tattoo. Pink ribbon tattoos are extremely meaningful to the women and men that wear such tattoos. Pink ribbon tattoos are used to represent breast cancer or a loved one that has.
I would like to say that I wouldn't regret this tattoo because its a cute idea, but honestly it kind of makes her hand look like a face. Choose either the sun or the moon. Or put one on one hand and one on the other. :) Neat idea though!