Can females in heat change their eating habits?

[Koteburo]

My Baby Bonkers, also known as Mulder is in heat now and yes I am going to spay her, tomorrow I'll call the vet, I just want to wait for the heat to go away for a few days to spay. I know it can be done while in heat but I'd rather wait a few days, she's indoors so my Queenie is not getting any consort!
Now I've noticed ever since all this heat issue started she has changed. She used to like EVERYTHING and Scully was the picky one, now I don't know what to give her anymore. What she accepts more is "Go" dry food, she doesn't want her EVO 95% canned, I've tried other brands as well and no. She IS hungry though (which is a good thing) she just doesn't want what I give her, today I even tried sardines and she ate one that was it, but at least she is still having the dry "go" trout flavour.
She doesn't have a hairball problem either like Scully and she asks me for food but nothing I give her seems to be appealing
I guess I'll have to stick to the dry food for now, it's grain free as well but could this be related to her being in heat?