If she is injured in a way that slows her down too much or makes her very vulnerable, I'd put her in a separate pen or cage right next to the other chickens while she heals. That way they can maintain their pecking order understandings & not have to start all over when she moves back in with them.
Once she's healed enough & not too vulnerable, you can use some ideas to help her out:
When you have "picking-on" problems in a flock, you can put some obstacles around to help out chickens that are getting picked on too much. These give the chickens something to hide behind, jump onto and run around while evading attacks from other chickens.
***Always be sure no blocked-off or dead-end areas are created where any chicken could get cornered.***
Sacks of feed, buckets, additional perches, trash cans, etc. can be useful.
Window frames (with either glass or wire in the middle) leaned against things can also be excellent for a flee-er to run behind and be protected yet be able to keep track of aggressor's travels. Window frames are even better if you can nail them so they are stand vertically and are at 90 degree angle to the wall. Then a fleeing chicken can also have the option to jump up and perch on the top edge to escape, and pursuer can't immediately chase her if she jumps down on the opposite side.
Lower-ranking chickens also appreciate shadowy, cluttered areas where they can hang out and not be noticed as much.
It helps to put food & water in some of these areas so less-dominant chickens still get plenty to eat and drink.