The face stuff does look like acne - is it only on the face? I would have expected it to clear over two weeks... do you use anything to wash her with? Or apply creams? Try no creams on the face for a week and see if there is an improvement and use plain water to wash with...
Re: nappy rash - I would probably get it checked if it is spreading. Could be something else going on such as an allergy, infection etc.

Probably wouldn't hurt to get both checked... or if you're due to see the MCHN you could ask them...

MG