If your boyfriend's daughter is afraid of the shapes and shadows in her room, you can give her a flashlight and teach her how to use it and see what the shapes look like in the light. There's a Curious George episode on this. You can buy a crank powered flashlight now for pretty cheap so you don't have to constantly replace the batteries. And having your own flashlight is cool. Yes, there will be a few nights of constant flashlight use, but she'll get over it.
If she's used to having someone in the room while she falls asleep, or is now preferring that, you can sit for a few minutes and then find odd jobs to do that will take you away for a minute or two. The AAP has this method in their sleep book and actually call it the "Odd Job Method." The key is to be quiet and unexciting but you really need to go to the bathroom, change the laundry, empty the dishwasher, etc, and you'll come right back. And then do. The key is for her to trust you'll return, relax and fall asleep on her own. I've gotten a lot of decluttering done this way.
We leave the hall light on for our daughter with the door open enough to provide lots of light but her face is still shielded. As she gets more comfortable, I can gradually close the door. I talk to her about what I'll be doing while she falls asleep and tell her she can probably hear me if she's really still and quiet. I also check on her 5 times while she's falling asleep. All I do is walk in and stroke her hair a couple of times.
You could also look into a sleep/relaxation tape for children for her to listen to while falling asleep. And you could try a longer nighttime routine to give her more attention when it's a good time. And give her more one-on-one attention during the day. You could also use an extra book as a reward for each night she follows the good sleep rules that you've laid-out. For me they're lying still and quietly. We all have nights we can't fall asleep but if she's trying, she gets an extra book the next night.