Since she is limping it sounds like she may have injured her paw. Possibly she could have stepped on a piece of glass and it's still in there. Or it could be a spider bite, actually it could be anything from the simplest of problems to the worst.
Unless you know what you are treating I would not do any home remedies. I would take her to the vets tomorrow. Remember the weekend is coming up and if you wait and it is something bad it will only get worse. In the long run she may not be able to walk at all and it will cost bigger $$$ if it's not treated tomorrow.
My feelings are it's better to be safe than sorry. I hope it's nothing serious and will clear up soon after treatment.