John Brown, a retired widower, said to Mrs. Adele Barber that if he could find a suitable house and if she would move into it as a housekeeper, help operate it as a rooming house, and take care of him, he would give her the house on his death. Mrs. Barber agreed. Mr. Brown purchased a house that he operated as a rooming house until his death five years later. During this period Mrs. Barber served as housekeeper; she prepared the necessary food and made other household purchases, always turning over to Mr. Brown the balance of the board money received from the tenants. She received no remuneration for her services other than her own board and an occasional allowance for clothing.

Mr. Brown made no provision in his will for Mrs. Barber, and following his death Mrs. Barber brought an action against the executors of his estate for specific performance of his promise. In evidence, Mrs. Barber offered the testimony of her two daughters, her son, and her son-in-law, who were present at the time of the original conversation between her and Mr. Brown. The executor contested the action. What legal considerations are relevant to a decision in this case? State whether Mrs. Barber's action would succeed.