That names like Admiranda and
Amanda were very rare indeed. Also that they would only really have been known to the people who used them, unlike common names like
Elizabeth. They were not part of a general stock of names (sort of like the difference between, say, '
Emma' and 'Calico' today - one is common and part of the popular name stock, the other is rare and would surprise people).
The
Amanda in the record is probably a girl bearing either the male French name Amand (women often bore male names such as
Philip and
Eustace), or a female form of Amand (probably Amande -
Amanda is most likely the Latinisation of the name).