Hi Paul my link to the Mable family is that with the death of louisa Brown Simmons in 1853 (his first wife) William married Agness (yes double S) Taylor Valentine my maternal great great great grandmother. When marrying Agness he also adopted my great great grandmother Fanny Georgina Rich Valentine. She was the product of Agness's first marriage to a George Valentine, Pastry Chef, of Bristol.
The Mable family were closely linked to the Walford family not only through marriage, but as highlighted in various diaries they were close family friends forever visiting and staying with each other. i would be very interested in seeing your family tree - we have hundreds of photographs from the 1910's - 1930's all with Christian or nick names and there is little doubt that the Mable family feature in some of them. My sister has cross referenced and identified many of them - perhaps more knowledge of the Mable family would help identify more of the photographs.