This is the knit halter top pattern by Monkeysbug. You can find it over on Etsy or You Can Make This.
It was well written, as her patterns always are, and easy to follow. My only slight disappointment is that it came out too short. Giana wears a 5 and this is the 6 pattern. Next time I'll make it a bit longer.
Love it though and plan on making a dress length one next!