I love her.

Tell me what do u think. So basically there is the person, a co-worker. So every time I see her or she talks to me my spirits get uplifted and I'm just more joyful. It's because she is a very cheerful person. And recently I've been trying to be more appreciative of her, because I'm usually more quiet and reserved, but she still always seems happy to see me, and just makes me feel... like there are songs that I hear during the day that remind me of her.
What is this? It's like I don't think of her, like I want to sleep with her or stuff like that, but I love her.