Sharing what I was told by Character Handler, Supervisor/Coordinator and Manager at Animal Kingdom.... "You can not save a place in line for characters - your entire party must be together to enter the line."
We were in line for a character. There was a woman in front of me alone. When it was her turn she said, go ahead (she had already let a few others pass.) The handler (older gentleman) heard her and motioned to her to meet the character. She said "I am waiting for my girls." He replied "I am going to have to ask you to step out and join the line at the back when they arrive. You can not save a spot in line." She went BALLISTIC. Then she was clever enough to get in his face and talk as quiet as she could but I was standing right there and she was so awful and offensive. Her daughters walked up as all this was happening and she went running off. After we were done we slowly walked in the same direction, I just had a gut feeling. Sure enough she found supervisor who had called a manager who had just walked up. The woman and her girls were talking to the manager so I approached the supervisor. Told her I saw the entire incident up close, heard what she said, she was awful and I had a feeling she was going to start trouble. She told me the woman wanted him fired for not letting them see the character. I told her what happened and she completely backed up the handler and asked me to stay to talk to the manager. I did. Manager said she was sure the woman was lying and appreciated me telling her what had happened and that the handler was correct in his actions.
It might have been one dad and three family members but what if there were ten dads and 30 people cutting ahead of you. And each kid gets a photo and autograph, then the kids photo together and then the whole family take a photo. The Norway situation was unusual, long lines out along the walkways made it impossible to monitor. Moving it to MK was to gain control of it.
My DS is disabled, loves characters and we wait in the lines, even when offered to cut ahead, I say no. When meeting Sandy Claws the CM allowed his siblings to wait in the line and him join halfway but we arrived to the line together and he sat at the entrance the entire time - not off doing other things.