Does it come and go? What causes it to pop up? It might be better to try to figure out what's causing her rash instead of just trying to treat it. Maybe she's sensitive to something in the lotion or soap you're using, or maybe she has a dietary sensitivity. Or maybe it's just heat rash. Your pedi can help you figure it out so much better than the Internet!
Call your pedi if you haven't already. If it's just dry skin and the lotion you're using isn't working I'd probably try a different brand/type but definitely call the doctor first just in case it's something more serious.
Re: How to treat
Does it come and go? What causes it to pop up? It might be better to try to figure out what's causing her rash instead of just trying to treat it. Maybe she's sensitive to something in the lotion or soap you're using, or maybe she has a dietary sensitivity. Or maybe it's just heat rash. Your pedi can help you figure it out so much better than the Internet!