When we were on the Easter Magic cruise, I dropped my wife, adult daughter and grandson off at the terminal, with all our baggage, My wife took my cruise docs, passport, credit card and off she went while I went to return the rental car. I was told all I needed was a picture ID for re-entry into the terminal area.
When I arrived back at the terminal from the rental shuttle, I was droped off across the street from the terminal at the tent. Walked across the road, showed ID at the gate and again at terminal screening and up the stairs.
My wife met me at the top and said all was done, check in completed. All I had to do was go to the CM who checked her in, show my photo ID and she handed me my KTTW card. You do not have to stand on line, just go up to that CM, that easy. Disney sure makes it easy that way.
My grandson was on line at about the 20th spot and played his video games with a bunch of other kids while we mingled with other DIS'ers going on the same cruise. When it came time to board we just got in line also.
Good luck on your checkin, it's really quite easy.
Kennyk