By having her name associated with a known criminal. There's no evidence she's complicit, or knew he was a mobster when she married him. It might be obvious in your mind, but there's no evidence of it. And, it's not just wives. Children of mobsters are on those lists, too, which is ridiculous.
I don't know why there hasn't been a legal challenge. Maybe there is some loophole that allows the authorities to do this. I'm saying it's bullshit. It should be challenged. That's all I've said all along.