Without going into detail as to why, I'll just say that I am pretty confident about the accuracy of my characterizations of these two. Dan could be a real jerk--not intentionally cruel, but just thoughtless. Wendi could be a spoiled entitled princess. I just want to resist the narrative that Dan was a saint and Wendi an evil lying temptress. The truth is they both had their problems. Their marriage was fatally flawed and my strong sense is they were both at fault for the marriage's failure.
As for her job at FSU, Wendi was what's known in legal academia as a "trailing spouse." If that sounds like something no one wants to be, that's because it isn't. Basically, Dan got a job at FSU and to convince him to come, FSU offered her one too. But what they offered her not the same echelon of job that they offered him, a tenure-track (TT) position. Rather, it was an NTT (non tenure track) position as the director of an immigration clinic. This is great work, and many people would find it more rewarding than being a TT professor, because you are not just teaching and writing but actually affecting real cases.
That said, NTT jobs are generally considered lower status because (1) they get paid less, (2) they do not come with the promise of lifetime job security (tenure), and (3) they are generally easier to get so not considered as prestigious. So yes, the lower-status thing was a constant point of resentment for her, as was the "trailing spouse" thing.
So it's not that she had trouble getting a career going, it's that Wendi was doing work that she had to do because she had to follow him from a large legal market (Miami) to a tiny one (Tallahassee). That said, she seems passionate about immigration (putting aside for the moment the irony of her being a strong critic of family separation), so directing the immigration clinic does not seem far from her area of interest. And it seems to have rankled her that she was doing work that she had to take in order to facilitate Dan's job, even if it was work she enjoyed on some level.