One of my pet peeves is when people hide behind emails or texts and will not discuss a matter by phone or face/face. I get the impression that this situation will not improve as you are also dealing with a husband/wife dynamic which seems a little shaky. I would terminate them as this drama is not good for you, your family and your business. Even if english is her second language, rude and insulting is mostly the same in any language.
you're right. I'm a ltitle nervous about it, but I just need to have faith that I will be able to fill the spot in the next couple of weeks