Hi
It is REALLY normal for her to start rejecting foods that she previously liked around this age.
I think what you do, first and foremost, is try not to worry about it too much - at least on the outside - so that the mealtime is not stressful. For you or her
Whatever you do I would not force her to eat anything. Even if a meal goes by where she has hardly put anything into her mouth - she will not starve herself!
Are there any particular foods that she will eat without a problem? If I were you I would offer at least one of these foods at every meal. If there is only one food she will eat, then repeat that one if you have to. And then in addition to the current favorites, introduce a new food or one that you think she might eat in addition to that. Be non-chalant about it and if she doesn't eat it, just put it aside. I wouldn't keep trying over and over again, just a couple of times and if she won't eat it then say "OK" and put the bowl aside. Hold off on giving that particular food again for a bit and try other ones.
What method of feeding have you been doing? Purees? Does she get finger foods her meals? Whatever you are doing you may want to try mixing it up a little bit, giving her a chance to do something new. For example, maybe mash up a banana or avocado and put a little on a spoon, and then lay the spoon on her tray and see if she is interested in taking it.
Hopefully it will just be a few days or a week and she will start eating "normally" again! HTH x