If I had this situation, I would probably tell her that "I CANNOT" prepare this return claiming the Child Care Credit for those payments, she can then decide if she want's me to continue.

I haven't done enough research to show you a reg, or other authorative document, just 44 years of doing this tells me that if something does not seam right or reasonable, I am not doing it, and to me this does not seem right or reasonable. I just sleep better that way.