My daughter is 6.5 and we all share a room and sometimes a bed (we all play "musical beds" and rotate between the queen and the twin). While I'm sure I could have nudged her to her own room years ago with no trauma we really haven't been interested in doing so. All three of us enjoy sharing our sleeping space so much and m husband and I don't intend to change it until she decided that she wants her own sleeping space.
Now, one thing I have insisted on from age 2.5 or so is that she go to bed first without us. I really wanted her to learn that it is possible to go to sleep without one of us there. Our routine is that we read a book, then do song, snuggles, and conversation in bed, and then my husband and I go out to the living room. That way I am not confined by an early bedtime, and her sleep schedule isn't reliant on me being there with her in bed. It works great!