Most Helpful Girl
It's weird that she's telling you that, but honestly I don't think there's much to worry about except that your girl might be one of those people that wants to know others are into her even if she has no interest in them. It's just more juicy info/drama.
Most Helpful Guy
if it's making you angry then I'd tell her to knock it off. it's wrong of her to do this. if she tries brushing it off again then tell her you mean it and you will leave her if it doesn't stop now. if she values you enough then she will stop.