Hello, and welcome, Gill!
Is Fanny's first name actually Eleanor? I saw, as parents to a marriage, a Thomas Mushero and Eleanor Butterfield. There are several Thomas (Mushero and similiar surnames) in 1851, so tread carefully in choosing the right one!
If you haven't already looked around the New Brunswick archives (BMD), give their surname index search a try. This link will take you to M, from there you add letters (for example add
ush) to get all names starting with that. Try all different letters, and you will find a lot more variations than you thought!
https://archives.gnb.ca/Search/VISSE/NameIndex.aspx?culture=en-CA&letter=M&datasets=012The nice part is, the image, free to download, is there for anything you find. On a quick hunt, I didn't find anything earlier for Thomas, but you might find some useful things on other family members.
Normally, on a Canadian census, Native would refer to a First Nations person, HOWEVER, New Brunswick was not yet a part of Canada. I have sifted through multiple areas in that census in New Brunswick, and in that column, the enumerator was supposed to put race and place of birth. Some enumerators did just that, but the one doing the area of your Thomas was simply referring to place of birth (lazy so and so!)
In 1861, Thomas was at Harcourt, Kent, New Brunswick. He was not there in 1871, but the census indicates that a John Mushero, farmer, resided there in that year, but died. In tracking him around, I found a delayed birth certificate for one of John's children that said he was Scottish. I mention this only as John could very well be brother, as his birthdate would have been around 1830 (and strangely enough, his wife was Eleanor, and daughter was Fanny.)
In the 1881 census, Thomas refers to himself as English.
