German School Holidays

Can anyone help me with how to get school leaves (additional) approved at a German school. I am getting married and my sister is in Germany with her family. We want to decide the date but my niece is just starting school this year from September and they are unsure if they will be able to come during Nov 2025 - Jan 2026. Need help with anyone who has been in this situation.

Will German school allow the kid to come to India during these months? What is the procedure to get approval from school. My niece will just be starting primary school.