Just because a name is on here doesn't mean people actually give it to their children! There are a lot of nicknames on this site, that doesn't mean they're used as full names. I don't think anyone would actually name their child Vi as a full name, but it's a cute nickname for Violet :)
Far too minimalist. Doesn't sound like a very mature ir sophisticated name. You can always call your daughter this, but it would be better to name her Violet. This is a lousy official first name, or a middle name.