Got tickets for my daughter and family on United TLV-EWR for Chanukah. Husband, wife, two young children. On the first flight, they were assigned random seats such that no two sit together. On the return flight, they weren't assigned seats, and there aren't 4 seats that don't cost extra. Do they need to do anything, or will United move people around so each child will sit next to a parent? On the return trip, will they be forced to pay extra just to get seats?