Thanks for the response. I would prefer to book online to avoid the phone fee and don't mind have 2 different reservations. I was worried more about my daughter's reservation getting canceled later on if they see that I did not purchase the unaccompanied minor service for 5-7 yr olds that they say is mandatory here: http://www.united.com/page/article/0,6867,1052,00.html

Do I need to call them after I make the reservation and point out that I'm the parent on a different reservation and have the same itinerary?