She's also old enough to the "reward" method. You give her stickers to stamp on a poster or marbles to save on a bucket/pot. When she reaches a specific amount of marbles/stickers she gets something she really wants (10 marbles/stickers might be a stuffed animal/toy, 20 marbles/stickers a tea party with her friends or an outing to the zoo with 2 special friends, you get the idea).
Usually each night she spends byherself at her room (even if you have to keep laying her down) she gets a marble/sticker. She can only claim the prize when she makes it for nights in a row... one disrupted night and she goes back to start over.
If she's doing great with you in her bedroom, i'd say it's a great start. You can spend anything from 1-2 weeks there go help her get used to her bedroom, maybe some makeover would also help (new sheets, a special poster, a pot of flowers) and keep talking during daytime about how great is to sleep in her bedroom, how much you like it there, things like that. After she's "convinced" her room is a cool place, you might want to start removing yourself from there, that is, having a long chat about how it's been fun to spend some time together but everyone needs their own room to rest. And you still love her the same and you will always be there for her but grown up girls sleep on their own and then you explain the marble/sticker method.
Good luck, you're just in the right track! Hang in there, there is hope!