There's really no way you can know this. Okay, fine, your "heart" tells you this. But how about listening to your brain for a second? You are in such completely different places in your lives, or you should be, anyway. What do you think will happen when she goes off to university and you're left sitting home wondering about all the fun she's having and all the new people she's meeting? What about starting a family? Is that something you would want? Because she's most likely not going to want that for quite a few years. These are things you should think about before you start anything with her.
My opinion is that it's really creepy for a grown man to go after a young, impressionable child. You can say, "Oh, but she's really mature for her age!" Whatever, that's what every older person says when they want to date someone younger. No matter how mature she seems, she hasn't had the same life experiences that you've had. Honestly, 17 year olds are morons. You were a moron at 17, as was I, as was everyone else in the world. They don't have the best decision-making skills, so even if she's into you, it's probably not the best thing for her.
Good. So stop talking to her at work.
