This might be a little out there, but...
Get a small strand of white Christmas lights...Millie has a small strand on top of her armoire, (30 lights in all) and it casts a beautiful dim glow in her room. Enought to sleep, but enough to see as well. I got them because they made her room look magical, but they ended up being so convenient for night feeds and such. So we still have them, and tbh I think we always will.
So...you put them up high, (on top of her curtain rod, on a high shelf, around her closet moulding, whatever) and tell her they are so that they are there because if she wakes in the night, now she can see to find her lovey, her blankie, to see that all is well, to (fill in the blank). Maybe when she wakes she feels disoriented, (especially if you were there when she fell asleep and now she is alone), and being able to see would help her. ?
About a year ago, Supernanny had a family do this for a 5 year old who came into her parents' room every night, and (if you believe what you see on tv) it worked for them. They made a huge deal of it, putting up the lights, saying how her room was so magical, etc....
Worth a try?