This is hardly a good idea.
Unless a miracle happen, most of the CX flights scheduled for June are placeholders. They won't happen.
Your best chance is to look at flights that are currently operating as an indication for the future. Remember that CX is currently flying 1% of its pre-covid traffic and under severe constraints for its crew. It is unlikely to vastly improve in 3 months.
Planning transiting, weeks/months ahead is not a good idea. So many bad things can happen with cancelled flights..I would not like an 11 year old be stuck at HK airport for a day or more. And you know the problems with SYD arrival caps in case she misses her connection.
If she really needs to travel, I suggest that you only consider a direct flight..