I had thought since both parents were mentioned she would be traveling with the mother while the father dropped them off. Are they going to be an UM? Or are they older.

I guess either way, good chance they would still help if you’re physically there as a courtesy. Just like GS call center will usually help - as a courtesy - with SOs/children PNRs if you call them (even for unrelated itin).

tho this is pretty uncommon case to walk people thru check-in when not traveling, so would be prepared for no..

it’s too bad United doesn’t have an AA Five Star equivalent that you could just buy for her (it’s a super neat 1st timer experience and same check-in as concierge key - bought it for my parents):
https://www.aa.com/i18n/plan-travel/...ar-service.jsp