It sounds like it first needs to be determined whether or not the document fell under the provisions of the law. I have not heard a final official judgement on that yet.Was this tearing up illegal or not.
Next, if it is an official document that falls under the law, someone needs to decide if Nancy is going to be prosecuted. IMO that is less likely to happen.
If she is prosecuted I think it is less likely that she would be convicted.
But the whole incident might be used as leverage, somehow, in the WH dealings with her.