Immenhof - The Adventure of a Summer (2019) on Netflix

Plot summary

Immenhof is the family horse farm, and since their father died Lou, who is sixteen, her older sister Charly and the young Emmie have been running it between them. They know horses but little about business. Leon, a city influencer, arrives to spend the summer at the stud farm and is not impressed by the place, yet the sisters put him to work in the stables as a free stable hand. Neighbor Matz keeps helping them out for free and has an eye on Lou. Jochen Mallinckroth, who owns the prestigious stud farm next door, holds their debts.