Jesus from Joshua. In post reformation England people had the family history to name their children after certain relatives, i.e., first daughter after father’s grandmother etc. So in order to deal with their aversion to the Blessed Mother and other Catholic saints but still name the daughter after grandma or the son after grandpa, the custom evolved of nicknames so that we have a Mary who’s nick name is Polly. Sarah’s nickname would have been Sally. John was called Jack and so on. Also, if your name is a common English word like Brown but it is spelled Browne, then your ancestors were English Catholics who were forced to change their names to identify them as Catholics.. sort of the 16th century version of the Star of David pinned to Jews in the 30s. Actually not sure about Sarah but am sure about Mary Polly.
Sarah, as in Abraham’s wife? Literal meaning in Hebrew is “princess”, I believe.