Even at our poorest, we still spent money on food for stray cats, and occasionally vet bills.
I've got a couple of random strays/cherished pets in my bed right now!
@Debater Slayer , I've trapped and taken several stray cats to the vet in my time. It will make a difference what tools you have available, and what your relationship with the cat is. Also, how bad the limp, and how long its been going on might make a difference on if you should interfere here. If she's a real wild girl, and the limp is slight, I might let it go for a few more days, and see if it gets worse. If it does, then there's the business of trapping...
If you have an animal trap or a kennel/carrier/pet taxi, this will be much easier. A trap will work best, but anything she can go into without getting out of will work. If you're using a kennel or other cage like item, you'll need to be near enough to shut the door after she enters. We've rigged things up with strings(Bugs Bunny style) when the animal wouldn't allow us to get close enough. Once you get her in, you're good to go.
Personally, my biggest concern is infection. You may need some help if there's any wound with infection; antibiotics take a bit to be administered. A break is possible, but I can't see a feral on the go leaving a bandaged wound alone. I am not sure how vets work over there, but you could ask if there's a possibility they could keep her there and do the meds for you, and you pick her up and re-release her when the round is over, if necessary.
Also, if you manage to get her into the vet, and can afford to do so, consider having her spayed!
If you have any other questions, please feel free to PM me. This thread has made me sick to my stomach, and I'll be leaving it after this post.