This was via the suggestion of a CM on our trip in March. There was no problem with it at check in at Beach Club either so unless something has changed since March, you may be able to do this.
My husband and I both had AP's. My sister and her 2 girls were coming to Disney the same time we were minus 1 day.
I booked both rooms. 1 with my name and 1 with my husband's name. I listed 1 of us in each room and the remainder of my family in 1 room and my sister and girls along with me in the other room. I was actually listed as a guest in both rooms so that I would have a key to show at the pool and b/c we were using the dining plan for my family. My sister and her girls were not using the dining plan.