Dear Ms Wise, my father is 70 and remarried several years ago after my mother died. His wife – like him – is a self-funded retiree and independently well off. He has always said he intends to leave the family home, worth about $10 million, to my sister and I with the proviso that if he dies first, our stepmother can stay on in the home until her death. What needs to happen for this to stand up legally, and what are the ramifications? Ben

A: Your father’s plan – to leave the home to his children while making sure his wife is secure if he dies first – is common, says MaryAnn de Mestre, principal at M de Mestre Lawyers.