Your attached interests me. My direct descent is via the younger brother of Henry Charles Buckett, William Frederick.
However, census returns for Henry Thomas and Caroline Buckett (Henry's parents) show your Mary living in with the Buckett's from 1861 onwards. On only one occasion did Mary disclose that she was Welsh. On other occasions, she was shown from Middlesex and Bermondsey. I have addresses if you are interested?
I know they were poor, especially after the death of Henry Charles Buckett in 1886. Did their descendants emigrate, or you still found living in the UK?
Regards, and hope this helps.