I just wanted to thank everyone for your help with finding interesting books on photographic composition for my mom. I ended up getting her The Photographer's Eye, Picture This: How Pictures Work, and two of Tim Fitzharris's books. She loves them and is making her way through each book. Her basic comments so far are usually something like: "I'm not creative, I'll never be able to get to many of those places, but I really love learning about all of it". Paraphrasing just a bit. Anyway, thanks again for your suggestions, they were very helpful.
P.S. I also ordered a copy of The Photographer's Eye for myself but haven't had any free time to read it. Looking forward to it.