Some ski schools offer an additional lunch option that typically includes a meal and supervision during their break.
Many schools are happy for you to arrange this with the ski instructor on the first day of your child's lessons. The option is normally only available for full day lessons and doesn't have to be booked for a full week.
Each school is different on how they organise their lunch supervision. If unsure, please contact your ski school via the phone number provided in your booking confirmation.