It is very important to know facts rather than small talk from friends. Sometimes people think they heard something, however, it is essential that you do not get your hopes up, especially when you do not know what is going on exactly. Don't keep your hopes you so you do not get hurt afterward if nothing really happens.
How can your friend get an information about someone she does not know? Well, could be possible but make sure you dig deeper into the situation. But most importantly, keep your feet to the ground and get to know the person well before engaging in any kind of relationship.