I would keep her separated from the flock for a few weeks to make sure she is not horribly sick with anything.
And when you do mix her in, do it slowly from behind a cage or enclosure in the run. Everybody sees, no body touches. Leave her this way for about 3 weeks. If you just throw her in with the flock they could kill her. This slow intro will help them accept her better.
After mixing her in, add more feeders and waterers so she doesn't get starved out and watch to make sure there is not too much aggression toward her for that first week.