Temporarily…
This person Susannah Martin (Watkins) is not shown in any records available, is not shown in either WikiTree or Family search nor the sources used by them. She shows only in Geni, without sourcing. The implication is that she was a late 3rd wife and had no children.
References to sources on Ancestry.com I cannot check nor confirm as I have no member access.
Also note that she has the same married name as the known 2nd wife Catherine