Families do tend to give different names sometimes, My husbands grandmother was Laura but always known as Kitty, (her mother was a Catherine), even her husband when writing to her,(we have a letter), addressed her as Kitty. Of course when she died (20th century) her proper name was used, but years ago names "stuck", Sarah often becomes Sally.
Don't forget we have Devon accents to deal with years ago too!!! and deaf vicars, the list goes on!!!
At least this one seems to be making progress. Keep it up Julia and let us know how you get on.