Hi Viks2030
Thankfully not had this situation arise for my DD (Y8), where absence hasn't been authorised, but we did have a long meeting with the Deputy Head of her secondary school when she first started about any possible absences for work. They were very clear that they would not authorise absence during any exam period and that for other dates they would review attendance (which would need to be above 95%) and need to be happy with her academic progress (a minimum wasn't spelt out for this

) On the few occasions she has needed time off, they have actually been very cooperative/ supportive and wished her luck with it all.
The main problem your friend has is if her DS is taking time off school, he is likely to need a licence to work/ perform. The local authority won't grant a licence without a letter from the school authorising the absence and the filming company won't be able to use your friend's DS without a licence. If the work is likely to take place during school holidays, a licence is still required, but the school's permission isn't.
In your friend's shoes I think I'd ask for a meeting with whomever the school like you to talk to in the first instance and then work it up the chain if need be e.g. form tutor, head of year etc, or ask the school who authorises absence and then request a meeting with them to have a chat about how much performing gives to her son's wellbeing/ confidence/ self esteem and how much more motivated he is likely to be about completing school work/ keeping up to date with his studies if he is given permission to take time off on occasion. The work itself has an intrinsic value regarding work ethics, being part of a team and understanding employer requirements and being commited about what he does. She might also ask (nicely

how demotivated he is likely to be if permission is refused.
Good luck!