Meanwhile, little boy graduated to his own big boy bed. The history of this bed goes way back to the French colonial days in Haiti. We purchased it on the street corner in the 1980's. Both our daughters had sleigh beds in their room when we lived there. We brought them back with us in crates. Now both daughters are using them in their homes.
So far, this arrangement is working quite well. Baby girl, who is still waking up to eat, is still in a mini-pack'n play in her parents' room. Hopefully, when she graduates to her crib, she and her brother will enjoy sharing a room.