I think 補習 is a choice but not a must. I have two girls studying in this school. We did not and do not plan to 補習. I feel like the syllabus of this school is rather reasonable. Not extremely challenging type. Parents will need to check on the homework and learning progress of the girls from time to time and provide support whenever necessary though. I think that would be suffice. (But I am a full time mom.) I have also checked with full time working parents of some p.5 and p.6ers who are rather top achievers in academic results in their classes. They also re-confirm to me that they had not taken any private tutorial classes so far. So, take it easy and you can always keep 補習as an option, but don't feel like it is a must. And don't forget 補習will take up a lot of your girl's free time and resting time. Good luck!