It should be, just monitor the situation.

Since you're not sure what the stray could possibly have (fleas, ticks, etc.) I would keep the cat away form your bun until you can get it checked out by a vet. It's always great to err on the side of caution just in case to make sure nothing happens.

yeah, that's why I want to keep my bun in his cage (It's higher up) and the cat away from it for now. He has a flee collar thing but I don't know how well those work?

Aw, that's great of you to help out a stray cat! I would exercise some caution too, just in case. I think keeping the bun cage a few feet away from cat access is probably a good idea.

Flea collars don't really do anything. They can catch adults, but they don't get all of them and the others go and lay their eggs. So the cycle keeps going. Getting a flea treatment from the vet is the only way to completely stop the life cycle.

P.S. thats so great of you to take in this cat

I'd be more tempted to keep them in entirely separate rooms, since a cat can jump onto a cage and stick its paws through bars. I think being extra cautious about fleas and scratching is important with a stray for the sake of your bunny.

Meanwhile, are you putting up signs in the neighborhood with a photo saying you've found the cat? Someone may be frantically trying to find it, rather than it being a dumped cat. If you don't hear from anyone, check anything that may be a lost and found for someone to report it to (where I live the housing complexes often have main offices so people could leave a notice there). You may want to find a local no-kill shelter if no one comes forward in a week. Otherwise, if you're tempted to keep it, the next stop is the vet.

We're going to be taking her to the vet as soon as possible because of how thin she is. We want to make sure she'll be okay but we can't keep her because my fiancée is allergic (though I bet he'd want to keep her xD ). I'm browsing through all the lost-pets boards and we're prob going to put some posters around. I'm not sure we'll be able to find it's owner but at least I've got a few co-workers who'd love to take her in so this story should have a happy ending.

We're keeping bunny and her separate though we let her walk around (under supervision so they don't get close). She seems to have gotten pretty quickly that she wasn't supposed to go play with the rabbit and she keeps away from his roaming area. Last night she seemed to really want to stay with us but after a day of living in our bathroom and understanding we weren't leaving her, she just hangs around her food and the little bed we made her.

thanks for taking the time to answer my question guys, it's much appreciated.