The way I would look at it is that your family are on one ticket and will most likely make it without rushing and if it is a little late and they want you to make the connection somebody will be there to assist. However, in the event of a delay, there are 7 flights per day with KA to KHH so the airline would have her rebooked and everything sorted by the time she landed in HKG (most likely with someone waiting at the end of the jetway to give her the new boarding passes in my experience).
I personally always book minimum MCT where there are plenty of connections knowing that the airline and airport set the MCT and its in their interest to have you make the connection. Well, at least with decent airlines like BA/CX/KA anyway, whereas IIROPS with airlines in mainline China has always been a nightmare for me.