The association with QC is still valid, at least until P1 students for this year. This is confirmed by the principal during a session with her and the parents.
For BPS, there will usually be about 20 girls getting into the school from am. Probably the same for pm too.
You can go to the link for HRGPS am and see the secondary school allocation for last school year.
//hra.hkcampus.net/