Question Author
Yes you and DSJ have read it incorrecty, the fanny white born in 1858 was i believe, as i said, the illegitimate daughter of Elizabeth white, the older sister of mary white and daughter of William white and Hester. I believe, after finding no trace of a fanny white in slimbridge, dursley or cam, that your suggestion was correct, Mary white born 1839 in slimbridge and in service from the age of 12, is fanny white DSJ's great grandmother. I have eliminated every other girl born in the area to w william white in 1839 and 5 years either side. If you re-read all the info I have written, i explain this. Elizabeth White was also I believe, the witness at Fanny and Henry's wedding.
I think I have shown this to be correct by tracing all the children and all possibles.