brother's girlfriend

My brother's new girlfriend is celebrating her birthday two weeks from now. I've met her a few times, twice or thrice I think, and she seemed like a nice girl. I want to give her a simple birthday present but since I don't know her that much, I'm having a hard time thinking of what to give her. My brother isn't much help either since he's also in the process of getting to know his girl better. I'm hoping to get ideas from you instead. Please help me ^^