I think you are giving her too much choice. I would research the types of diets available and when you are happy with the one you would like her to be on then I'd stick with that one. Dogs can sometimes be picky eaters so you really don't want to reinforce fussy eating behaviours.
Put down the food and if she doesn't eat say with 30 mins max remove and do not offer anything until next meal time (not even titbits or chews) Offer food again at next meal time and if still refused leave without until the next day. Dogs are not designed to deliberately starve themselves, unless they have learned that by refusing food you will give them alternatives, if you use the hard techniques you'll soon find the dog learns there is nothing to be gained from being picky so they'll eat.
I would only consider a change if your dog has diarrhoea, vomitting, appears constantly hungry despite eating, or looks and appears apathetic, other than that I would stick to one food.