This is basic advice concerning an Order for Division and Sale of Property and applies to married couples and co-habitees.
http://www.recentlyse...intly-owned-home.html
Unless there is a very special reason why the house shouldn't be sold, such as specifically adapted for a specific disability, then the courts very rarely refuse to grant the Order. The Court cannot grant the Order if the property is in negative equity.
Who has been paying the mortgage since you left? How much is your share of the equity worth? Could she buy you out?