6 month old not eating usual food

[mygrandchildrenrock]

My gorgeous puppy has always eaten her food, James wellbeloved, quickly and with apparent pleasure. However, for about a week now she isn't eating much at all. She's happy and not ill, she is teething, has lost loads of teeth in the last few weeks, but seems to have got fed up with her food.
If I mix something in with the food, sometimes she'll eat it, sometimes not. She's currently still on 3 meals a day, I wonder if she should go down to 2 and maybe she'll be hungrier.
I'm not quite sure what to do and don't particularly want to change her food. Didn't know if suddenly not eating much was common or not.