Missed this on, MG:

If it were rooms in my house I would not want to have them have locks on doors, in case of fire, heart attack, whatever. Locked up trunks etc. for valuables would be OK.

No, they can't lock them from inside-- but they can padlock from the outside when they leave for the day. Inside, there are only chain locks. Or they can put on a security beep-alarm (like a baby alarm on a sliding door).

That's a good tip about a lock-box for valuables, thanks.

~Susan