Help, Limping feral

Hello, hoping someone can help me with a problem.....In Jan. we received 2 captured, spayed ferals ( they were about 8 months old) and we left them in our the open garage over winter.  One, we have never seen, but the other has been very vocal and we have been able to have her come within 3 feet of us.  A few days ago we noticed she is limping slightly and we are at a loss as what the best option is.  She does run away and step on it and will not let us get close enough to touch her.  Should we try to get her captured and have the trauma of that along with the vet visit as well as what will happen when we return her to our house.  Or observe it for a few days and try to get her to let us hold her?  She is coming along on her own terms and we want what is best.  Yesterday she actually got within 3 feet of our dog also.    Thank you for our advise.

Welcome to The Cat Site. And, thank you for caring.
There are several current/recent threads that address this issue, including this one.
The rule of thumb (paw?) is: if the cat can put some weight on the paw, it probably is not broken. It could be a simple sprain, pulled muscle, in which case only time will heal that. It is possible there is some kind of wound/absess on the leg which causes the cat to limp. I don't know what the different clues might be; certainly, if the cat's appetite decreases, that could be a sign of infection.
I have had a few cats come to my feeding station (a/k/a trash dumpster). In one case, it turned out to be arthritis (best guess of vet); in one case, it was never determined what caused the cat to limp (best guess, possible old injury, cut; nothing showed up on various xrays); and in another case, time healed what ever was causing the limp (T-Rex). In the latter case I was able to get close enough to T-Rex to examine his paw; I didn't see any obvious wound.
I would continue to observe it, feed it a lot (high quality protein/cat food), and hope for the best.