You’ve already told us that. It doesn’t matter what names and insults the in-laws hurl at her. The important thing is for her to find relief somehow. Did you read my last post about asking some trusted guys to befriend this girl’s husband…hang out with him several times…and subtly/indirectly guide him and make him stronger??? You think it can work? Go read that post.
As for the emails she sent? Did she mention anything in those emails about being abused by her in-laws? If so, save those emails. You never know how they might come in handy as evidence.