I like the design, the dress and the clean lines of this. The profile and thee front figure don't really match when talking about nose lenght and chin height, so I suggest you work on that - even if I don't think anyone would notice if the two faces weren't so near to each other. The chibi one is... well, I can't find a better word than kawaii.
It's a really pretty picture and I like it a lot. But to be honest she doesn't look like a 16 year old girl. I think her body proportions and the shape of her body should be a little different. That's just my opinion though!