How have the courts interpreted a promise made by the testator in a testamentary devisee?

In Walker v. Boughner, supra, the testator, the grandfather of the plaintiff, promised the plaintiff that if she would come to live with and work for him he would make for her the same provision by will as he should make for his own daughters. In fact, he made his daughters residuary devisees but left the plaintiff nothing by his will and paid her nothing for her services. It was held that the promise made and the consideration for it both were of too uncertain a character to entitle the plaintiff to a decree for specific performance but that, in the circumstances, there was an implied contract for the payment of wages. This case on its facts is not a case touching upon the question of satisfaction of debts by legacies and is not helpful to the defendant.