One of the best things my kids ever gave me was Isotoner gloves.
I am a glove person, I admit, but the Isotoners make your hands feel like they are in heaven.
I don't really have any novels to recommend, although I love reading. I prefer things historically based. I'm not sure what your mom's tastes are.
My kids and I buy a lot of things on e-bay. That goes for books, clothes, jewelry. Not all things have to be bid on. That's my go-to place for relatives that are far away and I can have things shipped directly to them.
Just a thought. Of course you will need your mom's permission for something like that.
You could also visit a local bead store and get help with making her a necklace or bracelet. You might need Grandma or someone to give you a ride there, but they can help you make something really special. It's not that expensive. Trust me. You can also find gems to decorate a photo frame with a picture of you in it. Again, something you'd need some help with unless your mom has favorite photos around.
You can buy a clear plate or glasses and do an etching design. Craft supply stores should have everything you need for that.
Just get creative. I think your mom would love that most of all. I know I always did.
But....I have to say.......the Isotoner gloves were like Heaven on my fingers and I love them to this day.
Best wishes to you, sweetie.
I'm sure you will think of something your mom will treasure.