what about something like this?
http://www.soundaslee...eaker_Pillow_342872GE
would give her the comfort of the noise without it bothering anyone else and without the stimulation of the tv. it could actually be the watching the tv or dvd that is stimulating her brain too much and making her worry in the first place.
If she was mine I'd want rid of it. My boys has a couple of episodes of being scared in bed when they were toddlers, but it easier to deal with at that age. We just told them that when mummy and daddy weren't there, we had entructed their favourite soft toy to look after them and to make sure that nothing harmed them. We'd then have a good talk to the toy with them listening explaining about their duty and it worked a treat. It's easier when they believe totally in what you say and the magic of soft toys!