How much does a 2 month old kitten eat?!

Hi!

I’ve never used a site like this but I’m at my wit’s end.

How much does a 2 month old kitten need to eat!! I’ve searched the internet and I only get told that ‘kittens should eat as much as they can’. I understand that this makes sense for hungry kittens, but my kitten is not one of those.

FOR BACKGROUND:
1. She’s been to the vet twice since we got her about a week ago. I work from home so I’m able to monitor her very closely. First vet trip was for fleas, vaccines and a dewormer, second was to see why she wasn’t eating.
2. She’s been refusing to eat due to a fever — and I’ve taken her to a vet, she’s on medication and she’s improving, but I do have to syringe feed her or she barely eats at all. She already lost a quarter of a pound, which may not seem like much but it’s a lot when it takes place over the course of 4 days, when she was only 2.5 lbs to start. We tried different foods, and have been told it may be anxiety from her new home, but truly she is already VERY attached to us and seems very content with her home and it’s smells. She’s a chill cat, even without the fever.
3. Yesterday I syringe fed her and she absolutely hates every second of it. She’s improved a lot since I’ve been doing this (and it’s only been a day!) but she’s still a little shakey when she stands and isn’t quite feeling hot enough to start being her playful self, again. Today she’s hiding a little bit but I think that’s just because my partner (aka, her favourite person) is at work so she can’t sleep on my partner’s chest. I know she gets stressed when I feed her, but it’s necessary.
I’m syringe feeding her Royal Canin baby cat food mixed with water and I warm it to just room temperature every time before feeding. Yesterday I fed her almost every hour, a couple syringes at a time. I gave her a little more than half a can (5.8 oz can).
4. There’s been no vomiting or diarrhea. She poops on herself a bit sometimes, but she’s a Norwegian Forest Cat mix so very very fluffy.

I’m finally past the point of thinking she’s going to die, but REALLY just want to know HOW MUCH she needs to eat each day. Weight gain is the goal but I don’t want to make her sick.