Brilliant YA fun
How did Stephen King put it? Unputdownable. Despite its flaws (which I shall attempt to be constructive with later) it's not something I could stop reading. Ivy, as a protagonist, is incredibly relatable and what I've seen of her character arc in self-discovery is engaging and entertaining. I absolutely adore the chemistry she has with Storm, it's probably my favourite part of the book. And yes, he always deserves it. The characters are all interesting and engaging, and characterisation marches at a good pace, though I feel that individual character arcs could be made a little clearer. I don't know if it's an issue of slow pacing or not, but I feel right now as if this is a directionless story holding on to interest through world-building alone. I see the foreshadowing (slight though it is) and obviously this is going somewhere, but at the moment it feels as if any actual plot is being held at a standstill. Now, obviously Ivy needs to learn and her character arc is very important, but whilst incredibly interesting I feel as if the story, thus far, lacks real excitement aside from the events of part one.
Read the story now
As far as your style goes, I can't criticise you at all. The writing flows like music, gliding between sentences, and I can't help but be drawn in to this ridiculously interesting world which you've created.
The main flaw I found early on was Ivy's lack of a central motivation, something I see as vital to a protagonist, but as being directionless turns in to finally answering the call good and proper, I find myself not caring.
Overall, you'll find many books better, but none are like this. The author has carved out her own style and created a world you find yourself lost in. I hope that this does, one day, get published, and I look forward to reading future instalments.
Final note, a cheeky plug, if you're reading this then may I recommend my own fantasy novel, Cursed, an urban fantasy I'm sure is enjoyable (but then, I would be, I wrote it xD)