I'm 5'8" and have the same problem. If I purchase a women's cut jersey - the botton usually sit just at my waist. The pockets are up in the middle of my back and my arms just aren't that flexible to reach behind into the pocket to get a GU. I usually have to stop.

I am so surprise manufacturers have not consider that not all women are 5' - 5'5" or want to have they belly or backside show while riding. For now I either buy men's jerseys or when available loose cut or club style.