How to retaliate to a mean family member?

My neighbor/cousin's wife is insane.

Long story.

She claims my son broke her husband's/my cousin's windshield with a rock. She keeps changing the story, first 'he did it out of anger he told blah blah' she names the name of someone my son doesn't even talk to because she thought if she asked them if they would say it in court they would agree. They didn't. Then she says she saw him do it. Then she says someone else saw him do it. Then she says he did it to get back at her for running over his cat (but she didn't run over his cat).

There is another neighbor boy my son's age, but she doesn't pinpoint him because they have no money to pay for the broken window. Also this other little boy steals pills from his mother's medicine cabinet to give to her.

Also my cousin parks under a walnut tree. Walnuts have been known to fall from trees and break windshields.

We paid for this window anyway. Well, my dad did because he just wanted to 'keep trouble down'.

She harrasses my son while he's at the bus stop, telling him he's in 'her yard' to get out of it. When he's at the d*mn bus stop...just because it's close to the bottom of their driveway.

She came to my work and started crap, called in and tried to get my fired by saying I was rude to her. It didn't work because I had already warned my boss that she would do that, that's the kind of person she is. And my boss informed the higher-ups that this girl was starting stuff. Also they had it on camera.

She tried to get us evicted from our home. Again, didn't work, when my dad talked to the landlord he let them know the whole story and they found she was lying about everything she told them when she was trying to get us kicked out.

Now I'm to the point where I really want to play her game. I've been ignoring it but she keeps coming with all this crap. I need an evil genius. Give me something to do to flip this back on her and make her say, "Okay, I'm done, not messing with them anymore".