Both girls sleep in same room.
Miss J is in bed at 7.30pm - 2 books ONLY, kisses and then we leave the room. We have the lights dimmed in the room (more so i can see what i'm doing with Miss S) but then we let her go to sleep on her own in there. Sometime she goes straight to sleep, other times she'll read books and play with her baby in her bed for a while. It seems to work and we've not had a problem doing this.
Hope you can find something that works. x