As you don't give her name, I assume that it is Susannah Jones/Rowland(s). In 1861, this might be the family that William found (previous post) :
1861 RG9/4259/97/16
Penfoel, Penrhos, Cyniwyll
Evan Rowlands, 52, ag lab, b. Llanfair
Susannah, w, 40, b. Llangadfaen
Susannah, d, 9
Mary, d, 7
John, s, 4
Jessy, d, 1
Richard, s, 1 mth
All children b. Llanerfyl
brevitas