It looks like Fria is healthy again and ready to go back out to the coop tomorrow. She's been inside for a though. Things have changed since she's been out. Her mama has only had 2 to look after and has moved then up to the roost at night. I'm nor sure if she'll welcome Fria back or not remember her. I'm also concerned about sending her back out into the cold. Any advice on this or am I overly concerned?
Take her out in the morning, but stay with her if possible and watch how she interacts with the others very closely. There may be a little hazing to re-establish her position in the pecking order, which will probably be pretty low, but that is to be expected. Watch her for signs of stress though, in particular her wanting to be alone and fluffing up. Check her later in the afternoon to see if she has a spot on the roost near the other birds, if she is still on the floor, or is not near anyone else you will probably have to bring her back into a more protected/warm area for the night.
It may be a quick integration or it may take a few days to get her back into the flock, it depends on how accepting they are of new arrivals. It will be a real toss up as far as her mama recognizing her again... it would be great if she does, but a big if after a week or so away.