I sort of like it. It makes me think of the female gargoyle from Disney's The Hunchback of Notre Dame, so it's very sassy, no-nonsense, older-lady to me. It's hard for me to imagine it on a child or teenager, but nicknames like Vernie and
Verna make it a bit easier. The "lav" part sticks out a bit to me, though, so it also makes me think of sparkling toilets.
Overall, I think it's an okay name, but not my personal favorite. I prefer
Laverna to it.