How do I talk to my neighbor about her kids in my yard?

I don’t know if this makes me a terrible person but I hate when my neighbors kids or pets play in my yard. I know I don’t really use my front yard too much but don’t like having these kids play and leave their stuff in my yard (like toys, garbage and animal poop) it looks bad and what if they get hurt and I get sued? Plus my baby’s room is right by it and can’t sleep with all their noise. They have a front and big back yard can’t they just use theirs? I’m pretty shy and not confrontational at all so i don’t know how to approach this especially since they’re kind of ghetto.....(garbage everywhere, screaming kids, rundown house, tons of pets everywhere barking all the time, outside smoking all the time, and the mom is always yelling outside sometimes on the phone and even late at night). Please don’t judge me I just don’t know what to do...