First I want to give you a little extract of the already published chapters: It's about the main character Winter Simmons, who makes a bet with Seamus Finnigan at the Quidditch world cup. Seamus wins, meaning he's allowed to teach her Quidditch when they get back to Hogwarts, where they are both starting their fourth year, Winter in Ravenclaw and Seamus in Gryffindor. Back at Hogwarts they don't only come each other closer but also the best friend of Winter's big brother Cedric Diggory, which is like a second sibling to her, is chosen as champion for the Triwizard Tournament.
They were some grammatical mistakes, but nothing major. The most important thing that I noticed is about the two main characters and also the story in general. I really think that you move a bit too fast in the plot. There are at least three time or place jumps in ever chapter and that doesn't really fit. Also I think it's too early for Seamus too even like her really in that sense. I would think you could make the story a lot better, if you concentrate yourself one just one view. Probably better Winter's view, since it's always easier for a girl to write from the view of a girl. It's also better if you write really long scenes (maybe not like chapter 8, but longer and with more details. I mean, something happened before, something happened after) and a shorter chapter, then multiple short scenes with many time jumps and a 1000 word chapter. Of course it's always nicer to read a long chapter but it just isn't good if you have so many time jumps. Just begin with long scenes and one day you go back and can connect them. This really isn't easy but you will surely get better with some practice.
Also they should definitely have more practices before Seamus asks her out. After all, they are fourteen year old kids and in school. Let them get to know each other a bit before they develop feelings for each other. Additionally I have to say I never really saw Seamus as the boy who just falls in love with every girl who walks by.
I'm sorry right now, I can't really say anything about Cedric because we really didn't get much to read of him. But the few times he got mentioned he acted very authentically.
