I just found this post, but wanted to let you know what I did for my daughter. This will only work if your daughter bed isn't a loft one.
We used some fabric and made a big roll, like a door stopper, but long enough for the length of her bed. We got glitter for "monster repellant". And she helped me put the glitter in throughout the stuffing. Once we were done that part, we glued glow in the dark butterflies from the dollar store all over it. Oh, and ties, to tie it to the head and foot of the bed.
This way, no monster could hide under her bed. It worked soooo well. Because monsters don't go near glitter. (At least that is what my daughter told me.) She gave it to a younger friend at daycare when she wasn't scared anymore, and its working for that little girl too.
p.s. She also made me a picture of what she thought the monsters looked like. And we made it funny. Googly eyes, butterfly wings....ugly polka dots....and lots of glitter. She giggled whenever she looked at it!! Because we made them look rediculous.
Not sure if this is way too late, but I hope it helps.