Should I start a conversation like this?

[Brogan]

Every now and again my school ends early and I have to pick up my little brother from his school since he's on a full day.
I sometimes see his classmate's sister waiting on her brother there, too. I like her and I think she likes me too, although we haven't spoken to each other before. The reasons I think she likes me are:
1) The first time we seen each other and walked home with our brothers, she told her brother she liked my Green Day T-Shirt (I don't think a girl would to her brother that unless they liked that person, in my opinion)
2) When our brothers were being picked up from their Transfer Test, she was passing by in and was staring at me.
Should I start a conversation with her like, "Hey, your (brother's name) sister, aren't you?" talk about her music interest or hobbies and carry on a conversation there. If so and we do end up having a good chat, should I suggest that we hang out or something, but I'm not sure how! Can you guys really help me and give me advice about asking her out in the conversation, cheers.
Again, I rarely ever see her, and it's my brother's last year of Primary School so I don't want to miss a chance being with her.
This'll help me a lot, so thanks.

[Jessie]

Aw, this is cute. Yeh just go for it, you don't wanna keep putting it off until it's too late. Next time you're both waiting just go up to her and say hi, Just be friendly. Maybe find out her name and talk to her on facebook? So yeh, just go up to her and start a conversation. Hope things work out xxx