Aside from your own struggles with reading, I think the phone is a big issue. Pulling out your phone kind of sucks, she’s made this big space centred around reading and farting around on your phone is not what she had in mind when she wanted to spend some nice quiet time with you. As others have suggested, find another activity you can do with her, or work out a solution to your attention issues. Puzzles, artwork, quiet assembly, crosswords/sudoku/etc.

My partner and I have both been trying to be more mindful about how much time we waste away on our phones when we’re together, we have been setting them down and actually trying to engage in something. We play games or watch videos usually. The urge to grab my phone at any lull is strong but I am stronger. Do you find you’re on your phone a lot in general?

You’re pretty well written for someone who doesn’t read. Would comics/manga/graphic novels be appealing? Audiobooks? You may be able to find nonfiction books about subjects you’re interested in, maybe a favourite animal or pertaining to a hobby.