Hi Marydean,
I am not currently signing to W but in one of the book I've read, they use the same sign for breastfeeding, i.e. the milk sign.
I also wonder how babies can differentiate that, but babies are such clever creatures arent they
Perhaps you can use a different sign if you want to, such as tapping on your chest or other gestures similar to that?
I am sure someone here can share their own experience.
Cheers