Hi Derek,
I have just started researching my grandmothers line after working on my grandfathers and Ive found that its led straight to your post. My GGG grandmother was Elizabeth Taggart, a widow born Harrington approx 1803. Her eldest son James was born approx 1826. I see you have got a marriage between an Elizabeth Hill and a James Taggart in 1826 so he seems a good candidate for the deceased father. Can you shed any further light on this at all. Any help would be appreciated.