Taking in a cat in an emergency situation- health questions

Today I'll be taking a cat from a friend in an emergency situation.  Her 2-year-old son was recently diagnosed with cancer and is going through chemo.  They can't keep their cat because his immune system will be obliterated by the chemo.  The cat was at my friend's mother-in-law's house for a couple of days; apparently she's not an animal lover (and just generally not a nice person), and because the cat is stressed out from being moved, she's been hissing at the mother-in-law, who was too scared to sleep at her house last night and went to her sister's.  This morning, she called my friend and told her she wanted the cat out by the end of the day or she was going to "drop it off in the woods".

So, I'll be picking the cat up after work.  I've met the cat a few times before, and while she's not super-affectionate, she's perfectly nice and I'm sure she's just stressed out from all the upheaval in her life right now.  Over lunch, I went and picked up a Feliway collar for her to wear.  I would have done a diffuser, but one of my two cats had a bad reaction to one when we used it during our own move a couple years ago.  I'm hoping that the collar will help calm this cat, but not spread through the house too much.  My plan is to bring the cat home and have her stay with a litterbox, food, water, etc. in our spare bedroom, with the collar on, and hope that she calms down over the next few days.  And then we'll see what happens.  If she doesn't jive with my other two cats, I'm going to have to try to rehome her (really, really don't want to have to do that, given all she's going through) and what happens ultimately I guess depends on what happens with my friend's son.  My husband and I are going to do our damnedest to keep her separated from our cats for at least 3-5 days, longer if anything looks suspicious or if she's still being unusually aggressive.

Anyway, my main concern is that she occasionally goes outside and my cats are indoors (except for the occasional adventure on a leash or in their mesh tent.)  My cats are up to date on their shots, but I have no idea about this cat and I don't want to add to my friend's expenses or time, so I'm not sure what to do if she's out of date.  If she was an indoor cat, too, I wouldn't worry too much, but who knows if she's picked up anything outside.  I'll try to get a bit of medical history when I pick her up, but is there anything I should look out for?  Rabies would be obvious (hopefully her aggression is just stress-related and not that!), make sure she's not snotty around the eyes and nose.
 

Thank you for doing this!  My husband had cancer treatment and the only thing the oncologist said was "don't clean cat boxes and don't sleep with cats" but everyone is different.  I would get her vet-checked before I brought her into my house.  I would probably worry most about fleas and worms!   Good luck to you and I will pray for the child.

Thanks- that's a good idea about the fleas and worms.  I don't think I'm going to be able to get her to a vet before I bring her in the house, but fleas I can check for.  Worms would be visible in her poop or around her anus, right?  There's a few that aren't so obvious, though, I think, right?

Yeah, maybe it's because it's a 2-year-old with stage 4, they aren't taking any chances.   

I'll find out if she's microchipped, too, on the slim chance she gets out.  Luckily, we have a door that keeps the rest of the house separate from the laundry room where the back door is, and we rarely use the front door, so there's an extra barrier before the outside.

Good news! She was just at the vet 2 weeks ago, got checked out, is up to date on her shots, she hasn't been outside in six weeks, no signs of any issues!

We're keeping her in our spare bedroom right now. There was some hissing happening under the door between her and one of our other cats, but it's settled down. We've got her carrier out here and out cats' scratching pad in the room with her so they can start getting used to each other.

I have no idea why she was allegedly aggressive with my friend's MIL. I figure she's a good judge of character ;-)

So, we'll see how the next couple days go!

That's great news.  We have always been lazy and just dumped new cats in with the rest--at one time we had 10!  We never had any fights--maybe a hiss or two but that's all.  We are down to three, all old and too lazy to hiss or run.  A two year old with cancer--I can't imagine.  You have taken a great weight off of her shoulders.

When I was growing up, we had as many as 5 at one time and there was a strict social hierarchy, so I tend to err on the side of caution.  

When we got our first two, they were both adopted from the shelter I volunteer at.  They were there at the same time, but we adopted the first one 18 months before the second one.  Despite our best efforts to keep them separated, they met sooner than planned.  I don't know if they remembered each other (I don't remember them specifically interacting with each other at the shelter, though) or if neither one felt threatened, but they sniffed noses, and that was it.  Now they're like brother and sister.  There are occasional spats, but 99% of the time. they're very friendly with each other.  It will be interesting to see how they deal with a third.