My neighbor runs a day care out of her house. Everytime I come home there are several children?

using my drive way as home plate for kick ball. Sometimes the ball hits my garage door. Also i planted lily flowers on Sunday to find all the heads tore of on Tuesday. I also have chalk writing on my drive way, garage (sometimes), and mail box(sometimes). The daycare lady just sits there and watches this happen ( i am assuming). How do i go about telling her to keep her freakin children off my property? I just bought this house with my fiance in December and have no children of my own... but i am constantly out there picking up chalk pieces, shoes, garbage and watering my driveway down daily to clear off the chalk mess! I dont want to seem like a ***** but enough is enough!