In the family of "Robert Grosvenour, of Ruddeheath ..." and "Emme, second wife of Robert, 1322, 16 Edw. II. dau, of William Mobberley, ..." is listed "Raufe Grosvenour, esquire, 20 Edw. III. he died about the 30 Edw. III. 1356" who married "Joane, wife of Raufe, 16 Edw. III. 1342."
Note: This source combines two Robert Grosvenors (father and grandfather of Ralph) into one person, giving Margery as his first wife and Emma as his second. Jacobus gives them as 2 separate people, probaby on the basis of the fact that the younger Robert did homage in 1328, presumably indicating that he had recently received his inheritance.