The teacher is probably unaware ...
The teacher may even be unaware of who she is! It has been known, I'm afraid.
I suggest that you ask questions in the first instance: "Does she participate in class discussions?" "Does she put her hand up to answer questions?" "Does she volunteer for activities/tasks when you put them forward?"
If you sense a certain amount of squirming after a few questions, I think you would then be justified in pointing out that she does want to do those things, but "doesn't feel that she always has the opportunity".