[Facts] Re: Is Jeanette a genuine French name?
I think that Jeanette is either influenced by English and Scandinavian languages (immigrants used it in France) or it is a spelling variant that is rarely used, such as Seann instead of Sean.
In French Jeannette is the correct form as it is a diminutive of Jeanne. I think Jeanette would actually not even be pronounced the same in France under normal circumstances as Jean (masculine) and Jeanne don't sound the same in French.