To avoid a miles transfer fee, trips can be booked by using someone else's account.
Example 1: Passenger A can book a trip for Passenger B using Passenger A's miles.
Example 2: Passenger A can book two one-ways for Passengers A & B
Example 3: Passenger A can book a trip using Passenger B's miles. In this example, Passenger A can call reservations with Passenger B, and Passenger B can authorize miles.
Separate itineraries can NOT be combined. They can be "linked" by calling reservations to receive limited benefits such as seat assignments.
If any of the accounts are for a minor, the parent/guardian just needs to call in to reservations to use their miles.