Ah, so it's another united.com anomaly.

Since I bought the ticket while logged into united.com, I was looking at it logged in as myself in "View past trips" in My Itinerararies. That's where it looked weird as "2E" yet coach.

When I logged out and logged in to my wife's MP account number, and pulled it up from the regular "My Itineraries" list (linked to her MP number), it properly shows as "Upgraded First Class" and a booking class of NF.

Looks like all is well. Thanks for the confirmation that this is normal.

By the way, does anyone else think that labeling a link as "View past trips" that also lets you look at future trips, is a bit weird? As a software geek I can infer that probably one is looking at the united.com separate database of trips purchased online regardless of traveller, while the other is looking at the reservation system itself. But that's really half-baked software design and a very confusing interface for the customer.