All righty, I read this last night at some ridiculously late hour, so you'll have to forgive me if this review turns out poorly. I tried my best to take mental notes while I was reading - hopefully I can remember everything!
Right, so my first thoughts while I was reading this were about characterization, which coincidentally you had asked about in your request. I don't think you have anything to worry about here, especially with Gwen - she's far from a Mary Sue, she has flaws, but most importantly, she's relatable. I thought that the first few paragraphs did a very nice job with expressing her character and who she is, so good job with that. She's also very entertaining; I found her thoughts on Kat the Evil One to be highly amusing :) On that note, I loved the paragraph about James because I think it's helping me to see him more clearly (the bit about him not bringing girls home). Don't change it, it was good.
Then you wanted to know about flow. I think that overall there was a definite improvement in the flow in this chapter from the previous three. I barely found myself stopping at all while reading, and the transitions in the text felt very natural. There were very few grammar mistakes that I picked up on, so congrats on that. I guess the only thing that's really still bothering me is the dialogue tags, but we've already had a discussion about that, so I won't go into any more detail on that subject. But speaking of dialogue tags, I did notice how you started breaking it up more and varying the structure, like breaking the quotes in the middle instead of having just blunt "he said, she said" bits after each one. So I do see improvement there!
That being said, I would like to comment on something else this time. I think I may have mentioned this before in a review, but I really think you should put more contractions into the narrative/speech of the story. It did distract me a bit as I was reading and took away from the flow. There was one particular bit:
"Daddy! That's Ginny Potter! It is, isn't it? Why is she here? Is she part of this somehow? Or maybe she is starting her career again and she is transferring into Portree? Do you think that could be it? Oh look, she is looking at us now! I think she is smiling. Is she coming this way? I think she is! Oh Daddy, what should I say to her?"
All of those "she is"s should turn into she's, it'll make it sound much better.
Erm, okay. I think that was pretty much all I wanted to talk about... I guess I'll just leave you with my favorite quote then.
"Hi, I hope James isn't bothering you too much..." She said, ruffling her son's hair, as she reached us. The boy let out a grunting sound and tried to fix it back the way it was before. A task that couldn't be very hard in my opinion, as it had been quite messed up to begin with."
And Flashback James was so cute, I loved him! Also, I guess I'll just throw this in, I loved the friendship between James and Gwen in this chapter, especially at the end. I think it was a side of their friendship that we've never seen, and it was very sweet :D
Author's Response: Heey, glad to see you here again (:
Thanks. I've done a lot of work with my characterization, but it still worries me that it works for others too. That's why it's always nice to hear comments like that! And super glad to hear she's far from a Mary Sue, that's the most important thing!
Yeah, I'm working on that! It should start to get better bit by bit. Hopefully one day there'll be a chapter where you find no problems with the dialogue tags d: But nice to hear I'm improving!
The contractions are something that should also be better after this chapter. I haven't had time to edit these older ones yet, but it was around this time when I noticed that I was doing that. I hadn't even thought about it that much, just wrote and didn't pay attention to things like that. And you know, since this is the first story I let other people read, there has never been anyone to comment about that to me before d: but yeah, should be better in the next chapters (:
But glad to hear you liked it and think that about their friendship! I've had so much fun writing it, so it's nice to see other people like them too!
Thanks again! (: