ching, just wish you enjoy the time with the girl.. but I don't think there is any means to monitor her... she can go out to play and you won't know this...
10K a month is a good deal. Are you living with her or not? Its better to live with her if your personal life allows. Hope you don't have a tiger or girlfriend in HK.
Make sure you get a body check to make sure she doesn't have any sexyually transmitted diseases.