Pro tip: Get the 9:00am — opening time — tickets to the Louvre. Any other time and getting close to the Mona Lisa will take a LONG TIME. It wasn’t bad at all if you get to the gallery with a sense of purpose upon entering the museum.
There was a bit more of a line if you wanted a family photo with it but we didn’t do that. So we were maybe about 15′ away. You can’t get closer than about 8′.