Reading Jo Walton's brill Among Others, which is not a YA book but at the same time is, and she so perfectly sums up the condition of being a teenage/young woman, sometimes just a woman at all, that I had to share the passage:
There's a thing--I've noticed it often. When I first say something, it's as if people don't hear me, they can't believe I'm saying it. Then they start to actually pay attention, they stop noticing that a teenage girl is talking and start to believe that it's worth listening to what I'm saying. With these people, it was much less effort than normal. Pretty much from the second time I opened my mouth their expressions weren't indulgent but attentive. I liked that.
--Jo Walton, Among Others
Just think about it. And about whether or not your own expression is indulgent or attentive.