I second what everybody else has said - language skills are key, and it looks like once she masters that, there’s nothing that stands in her way in terms of becoming a citizen. My first career was as a language instructor, and whether you do an intensive program or just a night or two a week, classes and especially conversation practice helps and usually faster than people would think. Based on your profile, you’re in the Baltimore MD area, which should even have some free stuff. I would recommend small classes, preferably with other immigrants of different native languages. Also, improving her English skills doesn’t have to be uniquely geared toward the English portion of her N400 as once her skills are at an adequate level, the N400 part will be quite easy. As a plus, she will be a lot more comfortable when she is in situations where there are no other people with her language background.
Best of luck, and contact me if you want me to leverage my network to find something around the Baltimore area.