The narrative point-of-view seems pretty straightforward here: our protagonist, Jane Eyre, tells us her own story in a novel called, um, Jane Eyre. That's our first hint that it's all Jane, all the time.
It’s written in the first person, and the central character is doing the talking (or maybe writing). But Jane is—well, not exactly an unreliable narrator (in fact, she pays a lot of attention to giving us accurate detail)—but a narrator who forces you to read between the lines. Jane’s pretty good at telling us what’s going on around her, but not always too good at telling us what’s going on in her head.
Oh, sure, she explains how she makes decisions, and sometimes even explains how she feels—but often she seems a little too modest, like she’s suppressing her most intense feelings to try to seem calmer or more composed. Luckily, we get a lot of information about Jane from the other characters. Think about the part of the novel (Volume 3, Chapter 1) where Rochester tells Jane his history up until the point he met her and the way he describes his own impression of Jane when she first came to Thornfield:
"I found you full of strange contrasts. Your garb and manner were restricted by rule; your air was often diffident, and altogether that of one refined by nature, but absolutely unused to society, and a good deal afraid of making herself disadvantageously conspicuous by some solecism or blunder; yet when addressed, you lifted a keen, a daring, and a glowing eye to your interlocutor’s face: there was penetration and power in each glance you gave; when plied by close questions, you found ready and round answers. [...] There was something glad in your glance, and genial in your manner, when you conversed: I saw you had a social heart; it was the silent schoolroom —it was the tedium of your life—that made you mournful." (3.1.100)
Rochester claims that Jane may be stern and repressed, but he says he can tell this is just the effect of being at Lowood as a teacher and student for a really long time, and that with the right company Jane will loosen up a little. We think he’s right, but we would never have figured that out from Jane’s own self-presentation in the rest of the narrative. So, even though we can trust Jane on most things, she’s not always her own best psychoanalyst.