Upon entry of the boy's dorm the model status of the little kids gets set to -1 so they no longer spawn. This is done in a script, so you'll either have to edit that script or make a new script that could maybe just get when the current visible area code is the same as the boy's dorm, and then set the unique model status of the little kids to 1 or 2. (1 for 1 copy of them, 2 for multiple at once)
PedSetUniqueModelStatus(index,status) is the function. Index being the number corresponding to them in the default.ide, status being -1, 1, or 2.
