Her name was originally Hermione Jane Granger. About OoTP JKR told that Hermione and Umbridge shared same middle name. Delores Jane Umbridge? Wasn't it?
But in DH her name is Hermione Jean Granger (adressed when Dumbledore's Will was read). That's why it's confusing. Her name at begining of Series was Hermione Jane Granger but at the very end it became Hermione Jean Weasley.
Harry James Potter Ronald Bilius Weasley Hermione Jean Granger
and to tell آپ the truth I have been with the کتابیں and everything from the beginning and have never heard of this rumor about it ever being Jane. Anyway, its pretty cool- cause my middle name is Jean too.
In 2004, Jo told us her middle name was 'Jane' (WBD); however Rowling changed it to 'Jean" in Book 7, possibly so that Hermione and Umbridge wouldn't share the same middle name. 'Jean' is also one of the middle names of Rowling's daughter Mackenzie.