I have a big problem, Got any advice?

I really like my friends sister who is 15 and im 18. I dont personally know her but im friends with her older bro who is also 18. I tried messaging her through myspace, but he told me not to talk to her. He said thou he personally is ok with me liking her but its their Dad that doesnt let her date older dudes. So I was planning on talking to her on Halloween. Should I do something else? I have a big problem, Got any advice?
well maybe you can say that you guys are going as friends build a nice friendly relationship. if you really like her, maybe waiting is the way to go, maybe. if you can't stand that, then maybe tell her father and for his acceptance. it can go both ways, but at least it's worth of the try. maybe i say maybe too much. well best to ya! :) I have a big problem, Got any advice?
OK, so you don't personally know her but you really like her... And how's that exactly??? :-)

wrinkles