I think this could be a great hire or an awful one. Her track record, though limited, is quite successful at D2 and her 1 season at Marshall. Based on this, the positive is that I assume she knows how to coach basketball and coach college aged women.
The downside is she has no experience for the other logistics required to run a storied P5 program with a huge fan base and high expectations. She'll need to learn quickly how to recruit high level athletes and manage them in the new world of NIL. She's also joining a conference that is insanely loaded with top tier coaches, which means you're recruiting against them, game planning against them and have to make in game changes against them. For starters, next year the SEC will have Dawn Staley, Kim Mulkey, Vic Schafer, Kenny Brooks as proven goliaths, plus a slew of "up and coming" coaches, all of whom have proven track records at smaller schools or ample experience in major programs. Caldwell is going to be the lone outlier in the conference.
Do I think Tennessee could've found a much better candidate? 100% yes. This seems like a hire you'd take a chance on if you're a bottom feeder P5 program that fired a coach who couldn't turn around a program.
That said, if she's a great basketball coach and can quickly learn the other aspects like recruiting and handling the pressure, it could work out well. Have low expectations but will support her and root for her success.