Volunteer tutor needed: English writing for a motivated student in Kassel

My younger sister, Leni, is 13 and in Grade 11. Leni loves school but English writing has been a struggle since the school was closed during the floods. The university entrance exam is in July. We can't afford a private tutor, and the school's free sessions are full. We're looking for a volunteer who could spend an hour or two a week, in person in Kassel or online, for about twenty weeks. Leni is polite, hardworking and eager. We have a quiet space and a laptop for online sessions. I'll always be at home for in-person sessions. If you're a teacher, student or professional who feels comfortable in English writing, you could change the course of Leni's year. Even a small gift gets used right away and I'll thank you myself.