That sound like a good idea for a couple days to get her and the flock back in touch with eachother. There will still be some pecking when she is let out but thats normal for chickens with their ways. I would make sure you can devote a small amount of time when you release her to watch the birds for a few minutes just in case.
I don't know if this was bad/mean but I put my two meany pecky pants back in the flock, middle of the day, dumped them in the coop, just normal. I let them be pecked on. Problem solved. If they would have been majorly pecked on, I would have taken them back out, of course, but the couple pecks they got put them in order and they don't bother anybody else now.