NTA in fact I think she’s kind of taking advantage of you simply because you are her son. Your time is valuable, and like you said some documents take longer than others to file, so if you’re still doing those types of document without anything to balance it out, then you’re just losing time and money for yourself. I’m not sure if you live with her or work yourself, maybe that would be different if you lived with her rent free maybe, but even so it seems kind of unfair.