Only sound and not any reaction to flashing lights? I still have some sensitivity but it was much, much worse when my pain was not being managed as well as it is today.

I went a pain psych doc that taught me some coping strategies when I was at my lowest point (I couldn't walk into a mall without feeling like I was in a pinball machine at the time). Learning to breath deeply helped quite a bit. She might want to bring ear plugs or if there is any type of music she can tolerate, she could use headphones--I struggle with repetitive deep bass or drums in particular, classical music or jazz doesn't bother me.

I still struggle watching commercial tv, mostly because of the actual commercials, but if I'm in a flare I do better with calmer programming even than simply watching with the commercials removed, and tend to watch period dramas because there are fewer cuts in the editing--and yes it's crazy to be that sensitive, but you adjust--PBS is much easier than MTV for me, but that would be rough on a teenager for sure.