N.W.
I would be very careful about putting anything on her hands if she is sucking on them. I would consult your doctor first.
FYI- I sucked my thumb until I was about 8. My parents did just about everything they could to get me to stop when I was older and nothing worked. I had a large chaped/blister spot on my thumb. It went away very quickly once I stopped.
I really wouldn't worry too much about the chapped hands if they don't seem to be bothering your daughter. Will she substitute a pacifer?