She's only got one really, with two different versions each being equally… eh… beautiful in their own "special" ways.
1. The first "legitmate" version. You have been warned: https://www.youtube.com/watch?v=1dzh7Wuhp2c
The joke is that she's tone deaf/can't sing at all, which has been shown in two different occasions in the anime. Although, there is an instance showing that she can hum/sing lightly to herself and have it sound good, not to mention that her mother was a very good singer as well. Still, everyone has their faults and no one is perfect of course.
Since her native language is French, I like to think this is what her Japanese would sound like, especially if she was trying to learn the language or if she went through a weeaboo phase. It's cute, in an odd sort of way, I still like it.
2. Second "good" version of the same song. It's more representative of her VA, but it's still got some of Victorique's personality in it. https://www.youtube.com/watch?v=-E_CXSLd3h8
Honestly it sounds pretty beautiful, and sometimes I like to listen to it before bed. At the same time there's a sort of disconnect from it that I feel, since I know it's not her native language, but I know it's still "her" technically. Honestly, I've been trying to find some songs in French sung by girls/young women to sort of "build"/figure out what she'd sound like in French. No luck thus far though unfortunately.