What is her reasoning for claiming half, just the engagement? Engagements dont mean jack. If she invested $ into the business then she might have a valid claim or if her name is linked to the company in some official way. But if the engagement is her only reason then I highly doubt she has legs to stand on in court. Did you get a court order to shut down, or was it just her lawyer that said you had to? Coz I don't think a lawyer has the power to make you do that. Go get your self a good lawyer and see what they have to say. If it all goes your way, in the end, you should be able to sue her for lost profits and maybe some other things. Good luck...keep us updated.