Not many indoor tennis courts in HK, u can try LRC - Ladies Recreation Club & Clearwater Bay Country Club BUT I think they have a long waiting list to join ....
I have a Japanese friend who is a NTRP 4.5 - 5.0 player & always looking for advanced player ... if u like I can arrange a game for u guys. He plays in Quarry Bay weekly, pm me if u r interested.
Belinda