New England Graveyards like the Pan Burying Ground (which is on the National Historic Register) are filled with groups of gravestones which most of the time are of a family nature. Most times, husbands are buried with wives as in the case of Ruth buried (and leaning toward her husband).
Notice that Ruth's gravestone is somewhat smaller than her husband's gravestone and her design does match his.
However, Ruth (Ruth Barrett, as it says at Find-a-Grave) lived until 1841 and was 92 at her death. This is probably way her gravestone is a bit more ornate with the sun motifs.
Families try to have the husband and wife gravestones match for a feeling of permanence. It is not uncommon for a man to be buried with his first wife and not his second, especially if the first wife is the mother of the children.
The second wife can be buried many miles away if she went to live with an adult child when she was a widow.