Cindy lives in Townsville and writes to her sister, Jenny, in London asking if she and her husband would come and live with her in Townsville as she is very lonely since her husband died. She promised that if they came to Townsville she would leave them her house in her will. Her sister wrote accepting the offer and immediately organized for the sale of their home and the transportation of their belongings to Australia. Jenny and her husband moved in with Cindy and lived there for two years. A dispute has now arisen between Jenny and Cindy and Cindy demands that Jenny and her husband leave the house immediately. Cindy also advises that she intends to change her will to ensure that her house goes to charity and not them.

analyze the source to determine if there is a valid contract Jenny (and her husband) and Cindy and whether they can force Cindy to keep her promise to leave the house to them in her will?