Reddit reviews L173 - Master Theory Book 1

As far as learning to read music, Master Theory is a good place to start.

Specifically for the snare drum, I've heard good things about Podemski's Standard Snare Drum Method.

Chart Topping Drum Beats might also be a good way to learn how to read drum-specific music.

There are probably good free resources online too.

The "Master Theory" series of workbooks is what I got started on back in middle school. I'm looking through it right now and it should translate fine for adult learners too!

Here's the first one. If I remember correctly you probably won't need anything past book 3, after that it focuses on arranging.

There are tons of companion books published through Piano publishers who make graded material. Get Bastien's, or Alfred's, etc. theory books. They are designed to go with the lessons books, though she would have to do some "catch up" to the playing level. But you can do that in an ongoing manner in weekly lessons.

The "Master Theory" is also a good one.

https://www.amazon.com/WP205-Bastien-Basics-Theory-Primer/dp/0849752701

https://www.amazon.com/L173-Master-Theory-Book-1/dp/0849701546/ref=sr_1_1?s=books&ie=UTF8&qid=1549472583&sr=1-1&keywords=Master+Theory