The will of Nathaniel Wells dated 26 Aug 1677, proved 18 Mar 1682, mentions children [including] "Abigail, 20".
[Clearly the age is not specified in the will, as Abigail was not 20 when the will was written in 1677, and at best, the age could have been, though probably wasn't, specified in a separate probate document. This was a potentially misleading presentation by the author, making it appear that the will contains more description than it actually does, since a researcher might potentially look to this age as confirmation that he has the right Abigail listed as Nathaniel's daughter.]