Sally's limping

I have just introduced the new chickens into the pen with the old ones after weeks of just talking to each other through the fence. There has been a bit of fighting going on and Sally has come off worse. She is limping quite badly but there are no wounds to see only that she is a bit swollen at the top of her foot (ankle), her foot is'nt any hotter than the other. What can i do? she is resting as much as possible and eating and drinking, also still having a go at the others when they come near her. Do you think she needs to see a vet? or will rest do the trick.