Hi Lucy,
You were also asking about what happened to Mary`s siblings. This looks like Richard on the 1861 census:
19 Belvedere Place, Southwark Surrey
Richard Treeby, Head, M, 27, Hatter, Devonshire Stoke Devonport
Rosetta, Wife, M, 20, Southwark
Rosetta, Daur, 2, Scholar, 2, Scholar, Surrey Christ Church
Joseph Hy, Son, 1m, Surrey Southwark
Regards,
Mo