Here's how you could approach it:
* Phonetically: You could try to pronounce "Janellie" in a French way, emphasizing the "a" sounds and softening the "l" sounds. This would result in something close to "Zhan-el-ee."
* Closest French name: If you want a French name that sounds similar, "Janelle" (pronounced "Zhan-el") would be the closest match.
* Translation: You could try to translate the meaning of "Janellie" if it has one, and find a French name with a similar meaning.
Ultimately, the best way to say "Janellie" in French depends on the context and your preference.