Hi Helen,
I don't have the 1851 Census, but found these on the 1841 Census. They are the closest match I could find.
Hundred of Rhaeadr
Township of Maesgwyn in the Parish of Nantmel
Reference: HO107:1458: ED 1
BUFTON, David, 60, ag lab, Y, Thimble Hall, f10/p14
BUFTON, Alice, 60, , Y, Thimble Hall, f10/p14
JONES, Benjamin, 25, ag lab, Y, Thimble Hall, f10/p14
JONES, Elizabeth, 25, Y, Thimble Hall, f10/p14
JONES, Benjamin, 2, , Y, Thimble Hall, f10/p14
Maybe the Bufton's were Elizabeth's parents?
Hundred of Rhaeadr
Township of Cenarth in the Parish of St Harmon
Reference: HO107:1458: ED 6
JONES, John, 48, ag lab, No, Pantdulas, f5/p4
JONES, Margaret, 44, Y, Pantdulas, f5/p4
JONES, Grace, 13, No, Pantdulas, f5/p4
JONES, John, 9, Y, Pantdulas, f5/p4
JONES, Mary Ann, 6, Y, Pantdulas, f5/p4
JONES, Edward, 4, Y, Pantdulas, f5/p4
JONES, Elizabeth, 4m, Y, Pantdulas, f6/p5
MORRIS, Maryann, 28, pauper, Y, Pantdulas, f6/p5
MORRIS, Evan, 3, Y, Pantdulas, f6/p5
JONES, Daniel, 33, ag lab, No, Pantdulas, f6/p5
JONES, Jane, 33, Y, Pantdulas, f6/p5
JONES, Maryann, 5, Y, Pantdulas, f6/p5
JONES, David, 3, Y, Pantdulas, f6/p5
JONES, Jane, 6m, Y, Pantdulas, f6/p5
I've included all of these, as they are at the same farm. Possibly a connection between the two Jones families?
Hope this is the right group!
Sharon in Seattle