Sorry to hear she's not back to 100% yet- you are doing a great job with her keeping her healthy!
If she doesn't eat the larger kibble, she may just not like that particular food or yes, it could be too big/hard. After seeing Inky eat his food very often, last year I decided to switch to cutting every single kibble he gets into smaller pieces each night. I still count kibble (you can tell about how much makes one kibble) each night and it's not too incovenient. Inky started eating more right off the bat and has stayed eating more. I also feel better knowing he isn't working on just the first bite into the kibble for a long time, which I saw him doing with the whole pieces.
You could try cutting them into smaller pieces to see if she will eat them that way. She might be offended you are just feeding her crumbs, though.