She's already talking to you, dude, so she must trust you to a certain degree and suggests she's comfortable hanging out. I say listen to her and pick on a point she mentioned to steer some of the conversation to somewhere you really like. If she's yapping about, I dunno, how elephants are being used for labor, say something like... "On a related note, did you know that it takes some 3 days for an elephant's sperm to reach an egg? Crazy, isn't it?"
You must be well read though, like what the others have said, and know some cool triivia.
Just be natural when you divert the conversation. Since she was one talking about it initially, she's likely to forgive the diversion.
Make sure though that she's not just using you for a listening ear and only that.