Here's a few thoughts born of first impressions; hopefully you'll find them useful.

At first glance the story appears as an ambitious combination of world-building and adventure, though at least for the first two pages the world-building aspect takes the back seat, letting the adventure drive. My main concern is what adventure that is, exactly. It seems to start out as a lost romance, but then chapter 1 makes a sudden turn into an escape from guilt/crime theme, only for the second chapter to develop into a third distinct direction. So at this point the plot has no clear heading; rather several starts follow one another without a single thematic connection. It's also telling how emotionally differently the protagonist plays out for each of these different starts; she starts out as a damsel in distress, continues as a curse-torn vampire but then gets pretty quickly over the fratricide, and now is onto a retribution herself.

These mood swings may of course come together later down the line to form a unified character. Be that as it may, the story does have other points to speak for itself. The language is smooth and the balance between free and reported indirect speech reads quite nicely overall. I feel you use ellipsis a little too freely outside speech lines, but it's a topic of taste really. Some typos/missing words abound although not disturbingly to any extent. Your vocabulary is pretty rich too.

A final note about the world-building. At times it's a little hard to tell apart what the character knows about vampirism from how this is generally recognized in the society, and the point generalizes to other world-knowledge. So far you've avoided "exposition boxes", i.e. paragraphs which read like a history book, which I often see as the all-too-easy solution, so that's good. Perhaps you could use dialogue more for world-building purposes as well as the protagonist's thoughts?

I really enjoyed the story. I can feel that there's a lot of lore for the world bubbling underneath, and actual writing style you have is nice; it provides a lot of insight into Midnight without making it feel very 'heavy' from a descriptive standpoint with paragraphs of backstory or exposition or whatnot. I think a lot of the issues with the reader maybe lacking some knowledge(Mainly in how vamponies function and such) will get ironed out once there's further chapters; I haven't read a lot of vampire stories, but I think you also chose a good starting point, since it seems(To some degree I find) like a sort of dual discovery(Midnight learning to deal with her 'new' qualities while the reader learns them in tune).