Have flown US several TATL in economy since Oct. last year - in many ways pleasant flights, food not great but not as bad as I remembered it.
US might do a status match (UA did a status match for me from US years ago, and the reverse might happen - no harm in asking.)
US does do challenges
http://www.usairways.com/en-US/divid...preferred.html
Preferred status / cost Silver - $200 Gold - $400 Platinum - $600
There's surely threads on this on the US forum, but signing up for Silver would give you some status and if you did a TATL you could use United status for lounge access. Think if you sign up for Silver, but fly more than needed you get whatever status you've earned, roughly based on 4X what's flown in the challenge period).
Sorry about your daughter's experience - would probably leave UA just for that (well, am leaving for AA, but out of greed and a need to be appreciated). For the sake of others trapped w/ UA hope you'll write UA in the (probably vain) hope that the GA will get training (charm school? anger management?).