I had one bird who thought she was a guinea and wanted to roost with them. My guineas are "mine" only because I feed them regularly, they just sort of appeared one day. This particular hen could be locked in the coop for weeks on end, she still would go up with the guineas first chance she got. When they roosted up on top of my run, I'd just take her and put her in the coop. Once she went up in the big old Digger Pine, that was that, I wasn't climbing the tree to get her down. Mentally I pretty much said, "Good Bye" to her and let her do her own thing. It ended as I knew it would, one morning I went out and found her body. So, if you have your chickens as pets, I'd try everything and then some to get her to go in the coop. If they're pretty much just for egg production and you're not too attached, you can let her do her own thing but know how it will eventually end.