Getting to sleep - does TV help?

Hi. We previously had a policy of no TV after 9pm on weekdays (my 12 year old daughter has a TV in her room & goes to bed about 8.30pm). However I have maybe stupidly relaxed this rule recently because she was struggling to get to sleep & would lie in bed for hours, sometimes really scared because she'd hear noises, sometimes see visions etc. She said it's less scary and more relaxing with the TV on, so we let her leave it on, but she still struggles to get to sleep. Any advice on whether TV helps/doesn't help with sleep/relaxation? We have also tried audio books and relaxing music but she much prefers the TV :(. Are we being stupid letting her do this?