It most likely is that. Try giving her some human tuna tins(in brine), never
known a cat that doesn;t like it. Also Hills Science diet dry food seems to
be a definite hit as well.

It could also be more serious, such as problem in the mouth or teeth. Maybe
an ulcer or something. How does she refuse the food. Does she come and sniff
it and turn her nose away, or does she taste it then walks away. When my
Tiara had abcess on the lip, she would go lick off the gravy then go away
when it starts hurting her. That's how I noticed the problem.

Gee

One of my cats does this and it doesn't matter which can she gets. I think
they do it for Attention, having learnt how well it works! Almost like a
spoiled child, wanting something & not really knowing what they want except
Attention!