Does ТОЛЬКО here mean exclusively or just a moment ago?

a moment ago or not so long ago

Then we would not use the perfect - to avoid ambiguity.

Ok, Elena!!! Your link didn’t work, but you know best! After all - you’re here to teach English, not learn it.

No, I'm learning a lot here and I'm learning a lot from you! I just know that in British English they use Present Perfect much more often. And since 90% students are taught Brutish English in Russia, I can suppose that a teacher wants students to use Present Perfect in these cases.

You’re not thinking about context. The perfect is used when it has relevance to something in the present: “I’ve just read chapter two and I think I understand better why the main character is so bitter at the beginning of the book.” (= finished just a moment ago).But as a single statement of fact, it’s confusing to use the perfect because it can mean any of the two. So we disambiguate it by NOT using the perfect: I just read chapter two. (=finished a moment ago). I’ve just read chapter two (=I can’t tell you anything about chapter three).

I get it, but I don't think Таня Парышева wanted to use this phrase as it is...

Таня, если Вы приведете полное предложение и дадите контекст, можно будет сказать наверняка, какое время правильно употребить.

Tanya wants to know how to say Я только что прочитала полностью... which is I JUST FINISHED CHAPTER TWO.

I think ТОЛЬКО ЧТО (дочитала) - finished just a moment ago.
ТОЛЬКО (дочитала) - exclusively.

That was my initial thought - that’s why I asked in the first place.

a more natural way to say that is
я прочитала только вторую главу (а третью еще не начинала)

I agree. Дочитала is what's confusing there. However, that was something you can here everywhere.

Я только дочитала статью. Что хочу сказать? Статья довольно интересная.