can u help how to do this question with 25 marks with topic considerations and intentions to create legal relation? and also give cases

An elderly widow invited her niece to leave Philippines to come to Australia. The plan was for the niece and her husband to move into the widow's mansion to keep the widow company for the remainder of her life. The couple was promised that all widow's property (a substantial amount) would be willed to them. The niece left her lucrative acting career, and her husband resigned from a high government position, to make the move. After a few months of sharing house, the widow become annoyed, ordered the niece and her husband to leave and changed her will, leaving everything to charities. Can the couple take court action to enforce the agreement with the widowed aunt