FYI, Susannah died in 1801 so she couldn't be the mother of Isaac.
Died, on Sunday evening last, in the 25th year of her age, Mrs. Sussanah Bowles, amiable wife of Tobias Bowles esquire. This lady was a most tender and affectionate wife, a dutiful and most affectionate child; and perhaps none of her sex ever possessed in a more eminent degree, all those amiable qualities which particularly endear them to those that happen within the sphere of their acquaintance, than Mr. Bowles.
At present ‘tis sufficient to say, that by all those that had the pleasure of knowing her, she lived sincerely beloved, and died sincerely lamented.
Her spirit fled – “her angel, with a sigh, For angels weep when kindred mortals die,” ….
Source: Newspaper – Charleston – City Gazette. December 2, 1801