[Bann Valley] Anne, Agnes and Nancy

[<boydgray26@xxxxxxxxxxxxxxx>]

I am still chasing my Boyds in Aghadowey and Macosquin.  I have a great
grandmother called Annie Brewster (1851-1945) from Dromore in Macosquin and
wonder if she might be named for a lady called Nancy Gage (1776-1864) from
Collins in Aghadowey.  Although in different parishes, the two townlands are
only one townland apart.  Nancy would have been Annie's grandmother but I am
desperately short of proof.  I know Agnes and Nancy are definitely the same
name.  Can anyone tell me if Anne, Agnes and Nancy are all interchangeable?