I have this issue too, I used "lock for specific" sim on the master bathroom door in the parents' room since it has the only tub that doesn't work off the grid and is for the parent to bath the babies or relax, and I didn't want my child sim using up all the water reserve. I then go to bathe the baby and the child is napping in the bath even though I clicked the bathroom door an clicked "lock for specific" sim and chose her. I even check if the door was still locked for her and it was.
@whisperinwind87 OK. Thanks for the info
EDIT: To be sure: If you activity click on something inside the room while the Sim active and outside, does the child also go in ?
