I'm not sure what you mean by how you couldn't see the core items, because they are right below the starting items, as is common among guides. However, I do understand what you mean about more sections for runes, masteries, etc., but if you didn't notice, I already went into detail in the Notes for these. If you did notice them, which I have a feeling you might have, then what you are telling me is I need more detail, and in that case, I will make more specific sections for details about these things. I really liked your advice to add headers, because I had not thought of that. I will be adding headers for the items section soon. I also agree that the walls of text aren't the most attractive, and I will begin work on that as soon as possible. Being my first guide, all advice is greatly accepted, so thank you very much!

Hello! Your guide seems pretty compact and has pretty much covered the most important stuff. You could go more in-depth in gameplay or add a mastery, runes or matchups chapter.
Things that bothered me are the walls of text. You used BBCode in the item chapter but not in the rest of the guide. If you don't know, you can check out the BBCode guides for more information. Additionally, you should add headers. I couldn't see right off the bat what your core and situational items were. Even though I know how to build her, a new person might have troubles or has to go to the cheat sheet which disturbs the reading flow.