Jack and Jill / Jack et Julie

Jack and Julie

I had never heard of this film until I saw this had been released in France on Wednesday (25th).
Thanks to IMDB, I know that “Family guy Jack Sadelstein prepares for the annual event he dreads: the Thanksgiving visit of his twin sister, the needy and passive-aggressive Jill, who then refuses to leave.” Adam Sandler is playing Jack and his twin sister, Jill.
Sounds like a recipe for disaster? Yup, it sounds terrible AND the fact that the film has a rating of 2.9 on the same IMDB, and a Tomatometer of 3% makes me realise that I’m not the only person who thinks this is a worse idea than Alien Vs Predator (AVP is one of my 10 “Films I should not have watched, ever” list).

So what caught my eye about this potential navet? (Navet = turnip, meaning turkey (see definition 81 - point 1 in the Urban Dictionary)
The French title of course, which is “Jack et Julie”.
I could not find a single character in this film who is called Julie, so I started wondering why a character was actually renamed?
The only explanation I could think of was that someone decided that the people of France were unable to handle the first name Jill.
There are 2 ways this name can be pronounced by the French:
1/The “J” is pronounced “a l’anglaise” /dʒ/as in “joy” - which it would be by anyone with basic English skills or
2/ The name is pronounced “a la francaise” with the “J” pronounced /ʒ/as in “joie”.
With option 2, I guess there is potentially risk of confusion with the masculine first name “Gilles” - pronounced /ʒil/ (and unlike the Anglo-Saxon version Giles, it’s got 2 “l”s and the final “s” is silent), which could potentially mean that people think it’s a comedy  called “Jack et Gilles”?  
I really fail to see any sort of logic behind it all.

(This reminded me of one of my favourite South Park episodes, Awesom-o, and more precisely, this clip.)