I was an ENT in the Army. Got out in 2017.
If your wife is happy doing tubes and tonsils, and not peds airway, CI, craniofacial, or anything else that a general ENT couldn’t do just as well, then she’ll be fine.
But most people don’t do a fellowship in peds ENT so that they can turn around and do general ENT.
If you got really, really lucky and ended up at a major MEDCEN, and keep in mind the military doesn’t care much about doing your civilian spouse any favors, then she might be able to find a position at a local children’s hospital. Maybe.
It is unlikely that she would be able to work at the military facility because most of them either already have a pediatric ENT (and nowhere near enough complex peds cases to support them), or the facility is unable to support a peds ENT doc at all. Peds ENT was fairly competitive in the Army, primarily because they didn’t approve it that often because they don’t see it as all that important to blowing people up and because it’s hard to support a peds ENT doc. This means that the people who get those fellowships are usually lifers (or so close it doesn’t matter), and they stick to MEDCENs like white on rice.
The local children’s hospitals are usually short staffed and so if you ended up somewhere near a large metro area with a children’s hospital she might be able to find a job there, but at some point they’re going to find out that you may move every few years, and that’ll hurt her chances a bit compared with someone who wants a career.
Most MTFs are nowhere near someplace where a children’s hospital is on anyone’s mind.
It would be very tough on her career, I would think, and as stated above you should consider the reserves.
Also, if your wife is a pediatric ENT and you’re going in to almost any field of medicine - unless she’s already got crazy debt you’re going to be able to pay any debt you accrue off fairly easily. Unless you’re big, big spenders.