« Reply #4 on: Wednesday 06 September 06 20:28 BST (UK) »
1851 Hamlet Lower, village of Foxhole, Llansamlet HO107/2464 folio 684 pg 21
Richard Gwynne head mar 29 school master b. Swansea
Mary wife 29 b. Llansamlet
Mary Davies Gwynne dau 5 b. Llansamlet
John Borlace(?) Gwynne son 2 b. Llansamlet
Elizabeth Hopkin Gwynne 18 house servant b. Llansamlet
1861 Kilvey School, Llansamlet RG9/4094 folio 69 pg 34
Richard Gwynne head mar 38 school master b. Swansea
Charlotte wife 35 school mistress b. Cambridge
Mary Davies Gwynne dau 15 pupil teacher b. Llansamlet
John Borlase(?) Gwynne son 13 scholar b. Llansamlet
Richard Lloydd Gwynne son 2 at home b. Llansamlet
There is another entry - Mary Ann Gwyn age 4 whose father, Thomas, was a quarryman in 1851 HO107/3466 folio 468 pg 34, but I can't find any of that family in 1861, so with any luck this is the Maria you're looking for.
Cornwall: Allen, Bevan, Bosisto, Carnpezzack, Donithorn, Huddy, James, Retallack, Russell, Vincent, Yeoman
Cards: Thomas (Llanbadarn Fawr)
Glam: Bowler, Cram, Galloway, James, Thomas, Watkins
Lincs: Coupland, Cram
Mon: Cram, Gwyn, John, Philpot, Smart, Watkins
Pembs: Edwards (St. Dogmael's)
Yorks: Airey, Bowler, Elliott, Hare, Hewitt, Kellett, Kemp, Stephenson, Tebb