According to your family tree on thepeerage.com/p31165.htm#i311641 she was your gt gt gt grandmother. (George Taubman's mother.)
She and Henry Taubman married on 27 April 1811 in Braddan.

However Henry Taubman whom you have as b.1780 cannot have been the son of Thomas Taubman (bapt 26 Sept.1725 Malew) and Mary Moor (you have b.1726), when Mary would have been 54 had she lived. Mary Taubman als Moor(e) was buried in Malew on 30 Nov.1754.
Their children's baptisms, extracted from Malew Parish Register, were Thomas on 1 Dec.1751, and John on 19 May 1754.

Sue