I pretty much consider any reason to have portraits made a good reason. I was asked this last Christmas season to make a portrait of all the grandkids for a family to give to the grandparents. What a fun session.
With plenty of little ones, I always expect a bit of chaos to be a part of the experience. Though of course there was some, these kids did great and followed directions quite well. Using the studio layout to out advantage, we staged each layer of the kids in waves, starting with the oldest and ending with the youngest. Keeping the other kids in the lobby until we were ready for them created a great atmosphere of getting ready and set the expectation of entering the studio to make a photo and not just play around until things set.