(should I ask her how well she knows her first? or any other details, or say I think she's cute and we have a lot in common, or should I just straight ask her if she will introduce me?)
Most Helpful Guy
"I think she's cute, it appears we have a lot in common... is she as much fun as she looks?"
depending on a yes answer ->Introduce us then!
If you'd state you have a lot in common, it'd be weird as you don't know her really.
Don't ask too much about her, it'll seem like you don't want to ask the girl herself which'll come across as weird =)