Marijuana Possession

If someone that does NOT live at our house is using Marijuana on our property - can we be held responsible??? We live in Florida and have children. I just found out recently that a friend was using marijuana in their vehicle on our property. They were parked in our front yard - in our grass. Can the police hold us responsible, such as arresting us, searching or seizing our home, or take our kids away??? I am very scared and I want to know if this person should EVER be allowed to come to my house again. Thank you for any assistance.

Are these people your friends or your kids friends?
Cause if they are your friends and they have no respect for you and your family then.......
I was arrested once when my son ,then 18,bought some pot in our garage while I was upstairs. It didn't stick but I was labled a drug user for awhile. Just watch out for your kids,they don't need to be around drugs,you know that.

I have not training in law. But I did have three teenage boys(now 16,19 & 21)that have put me thru alot and make me wish I had.
Lori