Hello, cypress again. Just dropping another comment as I'm thinking of it. First - I do think, if you have a chance, fixing the spacing by reposting the chapters will make everything a bit easier to read. But that's obviously very minor.
Mostly, I'm noticing as I read that the interraction between the sisters and mothers and cousins all seem so light. The flippant mentions of dark magic seem almost out of place, and I can't really put my finger on why. Maybe that's just because, in my own mind, dark arts have a very heavy connotation, not just amongst those who fear it, but amongst those who use it. It's more of a fear/repulsion vs. reverence of dark arts, but they're always treated with respect, and a great deal of emotion, whether it's disgust and disdain that the dark arts aren't taught at Hogwarts like at Durmstrang, or the ominous feelings that weigh down scenes between the "good" characters when the dark arts are discussed. I suppose it sort of surprises me that Regulus would speak about them so openly and petulantly - that dark wizards and witches are talked about like they are everyday alternatives to other types of witches and wizards. I think there's a sort of buzz of excitement that comes from contemplating participation in something so taboo. A thrill that comes from conspiring that I'm not seeing or feeling when I read. The adrenaline must be rushing at the thought rather than just naive giddiness. I don't know if I'm expressing myself well, and maybe things will get darker and reality will settle in, but thus far, Ambrosia seems to have a very unwitting view of what it means to be on the side of the Dark Lord, the risk she's taking, and I didn't see any real reaction to the mention of Azkaban either. I don't mean to criticize. I swear I'm not! And I'm not telling you to write this the way I would write it. I'm just pointing out the feeling that I'm getting from the way things are portrayed. If that's your intention, to have Ambrosia glorifying the dark arts without a real appreciation for what is happening and what she's walking into, then it's good! If the dark arts are meant to be treated with awe and reverence, then, it hasn't come across. Really, it just depends on what you intended whether you might want to take another look, and since I've only read through Chapter 3, so far, this may resolve itself or become clearer as the story goes on.
Anyway, onwards we go! :D