Just a tip...
Kate just a thought as you have one of these names in your tree...
Nell, or Nellie was the pet name for Ellen, also used the other way around Ellen for Nellie.
Elizabeth variants Liz. Beth , Bess, Betsy, Betty, Eliza, Liza even Hetty and Elsie .
Others female names to watch out for are Polly
for Mary or Mary Ann.
Meg, Maggie and Peggy for Margaret and Sally for Sarah. Also (old-fashioned)
Sukie for Susan (as in the rhyme 'Polly put the kettle on').
Also worth bearing in mind are Nan, Nanny or Nancy for Ann and Jenifer being shortened to Jane .
On Censes forms 'The enumerator' took down the names which were given to him, also in some cases the form may have been filled in by one of the children as the parent may have been illiterate. Pet names or nick names used, were written in place of given names and in some cases that's why the place or country of birth is incorrect. ( Children often did not always know a parent or sibling had been born anywhere other than where they themselves had been born).
Hope this is of help to any others reading this also.
Chris