Post by wjhonson
When the last male heir of the Tilliol died in 1433, the heirs were his two sisters, one of which was Isabel who either was then or later married to John Colville
They are ancestral to Sarah Duchess of York among others
I am curious if anyone has a citation to any IPM that may exist to tell me how old Isabel and her sister might have been at the time
Not an IPM, but...
A post of 8/23/2014 by John Watson indicates that Isabel Tilliol was born ca. 1406 (said to be age 30 in March 1436). And Isabel died in 1438 aged about 32. The sources for this information can be found in the post, here:
The last male heir of the Tilliols did not die in 1433, but in 1435 or 1436 instead - again, see John Watson's post for details.
Isabel Tilliol and her sister Margaret are both ancestral to Princes William and Harry. I think that trumps Sarah Ferguson... :-)