Hope you are doing good. As for your friend, I want to say abuse in any form, be it mental or physical is not acceptable. By what you have mentioned it looks like she is not happy. In such case I would suggest that your friend try to talk with her parents so that they can talk with her husband family. If still things dont work then ask him to move out of the relationship. It is important that she try to make herself financially independent so that she does not depend on anybody. This way she will also gain confidence. Also what is important is mental support. Being a friend try to give her the support and stand by her.

Hope this helps.

Take care.