No, I don't know of the family but I see that the widowed James in 1871 (by now living in Moreton Valence, Glos - registration district Wheatenhurst) has with him a 5 yr old daughter Mary, b Moreton Valence. RG10/2625/36/5.
Possible birth reg for her then is as Mary A C Brain, Mar qtr 1866 Wheatenhurst.
If this is the right birth reg and Susannah gave birth to her then I'd think it may narrow down possible death dates for Susannah.