First of all, welcome to the forum!
The biggest lesson I have learned about chronic health conditions in cats is this: if, ever, I am faced with caring for a cat with hyperthryoidism, kidney failure, diabetes etc., I will go and join the group of experts who have already been dealing with that particular condition. These groups have been functioning for years and are made up of people whose collective knowledge and eperience far exceeds that of individual Veterinarians. If you think that you might benefit from this kind of help, you'll find the hyperthryoidism group at this link
In the meantime, she absolutely has to eat - or, she risks developing an extremely serious liver condition called hepatic lipidosis. In cats, when there is insufficient nutrient intake, the liver begins drawing on body fat...BUT, and only in cats, the liver takes more than it can process and, the liver itself absorbs the fat. So, you are absolutely right in assisting her to eat.
For starters, get a pediatric medicinal syringe (or a large needleless syringe) and some meat-based baby food (without onion). You can mix some water into it, and then, CAREFULLY inject it into the side/corner of her mouth, NOT "down the hatch" as she could easily aspirate on it. Ensure she gets extra water the same way. And, please, don't take a wait-and -see approach to this - don't even wait until tomorrow. Get what you need and begin this now.
Just as with hyperthryoidism, there is also an online group of people with lots of expertise in assist-feeding cats. You'll find them at this link
. That group is an offshoot of this website focussing on assist-feeding