Find-A-Grave currently has a birth year of 1751 [http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=75887798 FindAGrave link], whereas Geni and most MH Family Trees have a birth year of 1759.
However, the text of the Find-A-Grave info also has a rather incorrect birth date for her husband ''(son would be born at his age 14, and differs from his memorial [http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=75887747 FindAGrave for Joseph Jr.] ... which also differs from what is on Geni ...)'', which doesn't lead to confidence in the information currently on that memorial entry (no picture of a marker yet, either.)
The one son noted on Find-A-Grave would have been born when Susannah was either 39 or 47 (depending on which birth date is used).
Susannah's death date on Geni is the same as her marriage date ... which is probably incorrect if she & Joseph did have 5 children.
These are a few of the issues to resolve...