In 1861 Mary Onions aged 14 is recorded as the daughter of Richard Davies 26 and his wife Hannah, 35. Richard is too young to be the father, so it is likely he is the step father. This needs to be confirmed. Birth certificate for Mary and marriage certificate for Richard and Hannah have been ordered.
Hannah was a widow when she married Richard Davies. She had previously been married to Richard Onions and Mary is their child.