The people who ruined the name Yenta came from the short-lived secular Yiddish world (der Bund un der shund) and it is a pity we can’t reclaim it – but don’t try to do so at your daughter’s expense.
Yitta, Yetta – both exist and I wonder if they come from the same source as Yenta as letters and sounds arbitrarily dropped and were added in different parts of the Germanic speaking Jewish world.
Gentille in French could be Adina or Eidel (not an exact translation because gentille isn’t really gentle in that sense – but these are the only 2 semi-translations I can think of that are actually names – Chasuda is not really a name and that is the exact translation of how the word gentille is used in French today.) so that Adina Yitta or Eidel Yitta (depending on which is more accepted in your circles) is a good solution.