Well she cannot sell the house without his consent, they both own the house and any split would either have to be by agreement or through the Court. If she wants a legal separation leading up to divorce then all of the marital assets and marital debts will be listed and split, taking into account the needs of both parties and of course of the children. If she earns more than he, then when they separate there would be the question of maintenance and who would be covering the bills and the mortgage etc. He would also be entitled to some of her pension and she his - it can all get very complicated and expensive unless they agree, but from what you say it sounds like he is not going to.