Hello Bella, I have located the Census for you Census 1871 Mary Williams age 44 M Housekeeper born Pembrokeshire Mary Williams age 18 U/M daur born Monmouthshire Ebbw Vale Mary Jane Evans age 12 grand-daur born Monmouthshire Ebbw Vale John Evans age 6 grand-son born Monmouthshire Ebbw Vale Sarah Jane Evans age 3 born Monmouthshire Ebbw Vale 15 California Row Town of Ebbw Vale. If you have obtained a copy of Sarah Jane's birth certificate this will relate to you the connection to the Williams, it could be that the mother of the Evans childrens was Mary Williams daughter and that is why they are listed as grandchildren, and being that they were lodgers in 1881 the mother may have died after Sarah Jane was born. Regards Barbara