We flew back from Japan (a long flight!) and the woman in front of us had her little yorkie out in the seat next to her for the entire flight (Business class). You're leaving from the east coast, and could stop in London, before heading to Paris which would break up the trip and make it not much more than coast to coast.
We also know someone who took their Yorkie to Hawaii. That is a 5 hr. ride over and 6 hrs. back. So it can be done.
Pee pad train her so that she can relieve herself on the plane (in the bathroom). That would seem to be the biggest problem. As long as she is used to being quiet for several hours I think she can make it. And WHAT FUN to travel with your baby!! Do your homework and have a great time...