Flipping through the pages, there were a couple of other women with the Ww.
I did note that the burials for children had their parents named, and married women had "wife of so-and-so" noted.
I did find one written Widw, which makes me think you are correct about "widow".
There are lots of Bird and Tooth families in that book; it might be worth your while to do a page by page look-see!
I have no idea of what the abbrev is after the Ww. It only appears on burials, and virtually every burial, except for the odd man here and there, such as Joseph Bird. It could be a latin abbreviation, as just prior to the 1769 clipping attached, showing the Widw , latin was heavily used in all entries.