I'm lucky because my bed is very high. I have two sets of stairs for them to get up there, one on the floor, and the second set on a bench that go up the rest of the way. When we don't want them up there, we just pull up the first set and listen to Luna whine to get up there the whole time
If we were to lock them out of our room, Luna would cry and Izzy would violently scratch at the door. They HATE a closed door
Good luck, hope you find a solution. Hey, maybe a special chewie that she only gets at that time will occupy her while you are "busy"