Tony - well spotted. It's taken me a few years to dig through the complex relationships. Sarah Reynolds was first married to Thomas Carter, then she went off with George Kemp (without marrying him) who died in 1879 (in the house next door - 18 Silver Street). She then married Edward Williams (possibly bigamously). In the 1881 census, there are children from the Kemp relationship and also from the Williams relationship. In addiion, there are two other persons, at least one of whom is a brother of Edward Williams.
Amelia Chambers does not appear in the 1891 census entry for the family (now at 21 Silver Street) nor do the Williams relations.
