You can find the girls in the shelter when they are resting alone.
1 - Put Ai to rest (Yellow) and anyone else in the shelter to work.
2 - Go to the bathroom at the same time you put Ai to rest, she will be taking a shower.
Here in this work schedule, Mary can rest at 8 am, everyone else is working on something.
If you go to the bathroom, pool, gym or living room at 8 am, she will be there.