Is tuna ok for a 5 month old cat?

My 5 month old kitten has not been feeling well this past week. Took her into the vet yesterday and they couldn't find anything wrong with her so they gave her a shot of cerenia for nausea since she hadn't been eating, been throwing up clear liquid and has diarrhea. As soon as we got home she went straight to the food bowl so I thought everything was fine but now she's back to being "picky". I've tried several different types and flavors of food but the only thing I can get her to eat is tuna. I mix it with her wet food but even then she only eats a little bit. She is drinking and using the restroom still and so far has not thrown up since yesterday before I took her to the vet. I noticed this morning that her poop seems to be solidifying a little bit but there's still diarrhea. Is it ok to keep giving her the tuna and cat food mix? Also I have another cat who is almost 7 months and if I don't give him some too he steals her food. I've tried separating them while they eat, putting her in the bathroom, but she doesn't like that.

The most important thing is to get her to eat. If she's been feeling sick and not eating properly anything that she can keep down is OK. Too much fish isn't good for cats long term, but it won't do her any harm for now.

She may have just had a stomach bug that was hard to detect. I'd give her a few days of the tuna mix if that's what she likes then try to wean her back onto her regular food once she's back to normal.

Here's an article about fish based diets.

 [article="31650"]Can I Feed My Cat A Fish Based Or Fish Flavored Diet​[/article]  

Ok thanks! I just wasn't sure because I had been reading that it wasn't good for cats. I'm going to try some tuna flavored wet food today to see if she will take to that. The vet suggested doing a fecal test and antibiotics just in case of worms but that would have been over $200 for everything! I just started her on revolution and she was perfectly fine last week so I don't think it's worms. She was a stray before we got her so maybe the change in diet has upset her stomach. We've had her about 2 weeks now and the first week she was fine.