11 year old daughter not sleeping

I saw this forum and was interested in what has happened to your 11 year old boy who was afraid of spiders? my 11 year old daughter has not been sleeping since she started secondary school in late September. she will not sleep when she goes to bed and waits until i and my husband have gone up to bed before sleeping. she then wakes up in the middle of the night saying she cannot sleep and is afraid! she thinks she is the only one in the house awake and so she is scared.she comes into our room and wants me to sleep with her. i did initially and thought she would just not wake up eventually but it did not work. she still wakes up and i have told her that she cannot come into our bed and that i am not sleeping with her. i told her there is nothing to be afraid of our room is across the hall. she now puts a pillow on the floor and sleeps next to our bed. we are all exhausted from this disrupted sleep and i am at a loss on how to deal with it? i have done the good cop/bad cop routine and nothing works. nothing is bothering her at school but she is just afraid at night!