Whats a good book to read to my partner at night?

My partner has crazy insomnia and would put on sleep stories to help distract from her thoughts and help her drift off. Last year I got back into reading (Stephen King) and told her I might as well read to her instead of her sleep stories. It works great! I actually love reading aloud because it helps me actually read instead of skim. And she falls asleep within like 10 mins. However, I realized that some of Kings work seems to be giving her nightmares (she will jump awake, or talk in her sleep while I'm reading, clearly upset).

Any recommendations for quality stories that would be good enough to hold my interest, but not dark or disturbing? I tried Demon Copperhead and she hated it because it was too real and the subject matter is pretty depressing. She would stay awake listening and just getting sadder as I went on.