Ok... Assuming that this girl isn't the mean type, she's not talking to you BECAUSE she likes you, and the very thought of trying to talk to you is probably very embarrassing, and she figures that if she even tries, she'll say something stupid or be rejected out of hand. She probably wasn't even trying to make you jealous(at least this time), and chose your friend as her partner, because she saw it as a chance to get to know someone that could tell her something about you(I'm giving her the benefit of the doubt, here).
So - assuming I'm somewhere close on this, I'm afraid there is no happy answer here.... Heh. Because you're going to have to do what you are frustrated that she won't do: You're going to have to be the one to break the ice... You need to talk to her first.
Think about it, if you like her, and she likes you, and you're asking 'why won't she come up to me?', what makes you think that she's not wondering why YOU won't come up to HER? Boy/Girl (and Man/Woman for that matter) relationships are very complicated, and you have to remember that anything you are wondering about her, she may be wondering about you... She's not just a girl, she's also a person, just like you are, so you have to realize that there may just be an issue of shyness, or embarrassment. After all, you haven't tried to talk to her, have you? Why not? If you think she likes you, and you obviously like her, why haven't you spoken to her? Heck, unless your teacher had insisted on the girls choosing their partners first, you should have spoken up and said "Hey, how about I be your partner?"
Just a thought, and hopefully something to think about.
I'd recommend coming up with some simple question you can ask her, like "Hey, my friend said you worked really well on that last assignment, do you think you could give me some ideas on ______?" (insert whatever topic you've decided on) Frankly it can be anything from music, school assignments or whatever. The point is to get past the part where the two of you haven't talked about anything. Coming up with some simple question, then asking her specifically, gives her a chance to talk to you about something that avoids whether you like her, or she likes you, and yet shows that you are interested enough to go out of your way to ask her opinion. It also allows you to be friendly, without having the pressure of asking her out on a date, before you even know each other.
I think you will probably enjoy how easy it is to go from something as simple as "Hey, what did you get as the answer to problem #3 on the math assignment?" to "Thanks, I wasn't sure I got that right... Say, are you doing anything after school? I was thinking of going to get a sundae at that ice cream place downtown. You want to come with?"... And from there, you're in a position to let things go where they will.
Just don't act too cool, or she may think you're just teasing her. Be open, honest and casual, and see where things go. You'll be just fine. And remember: A casual offer to go for a sundae, or some fries, or even just a soda, lets you have to freedom to say "Nah, that's ok, I just figured I could repay you for helping me out, it's no big thing." ... In the event you get shot down, and she's not as interested as you think... It's just a simple way to open the door for her to talk to you, and then let her make the decision if that's a door she wants to walk through...
Hope this helps, and good luck. Oh, and if this does help, remember to rate this answer appropriately. Thanks.
So - assuming I'm somewhere close on this, I'm afraid there is no happy answer here.... Heh. Because you're going to have to do what you are frustrated that she won't do: You're going to have to be the one to break the ice... You need to talk to her first.
Think about it, if you like her, and she likes you, and you're asking 'why won't she come up to me?', what makes you think that she's not wondering why YOU won't come up to HER? Boy/Girl (and Man/Woman for that matter) relationships are very complicated, and you have to remember that anything you are wondering about her, she may be wondering about you... She's not just a girl, she's also a person, just like you are, so you have to realize that there may just be an issue of shyness, or embarrassment. After all, you haven't tried to talk to her, have you? Why not? If you think she likes you, and you obviously like her, why haven't you spoken to her? Heck, unless your teacher had insisted on the girls choosing their partners first, you should have spoken up and said "Hey, how about I be your partner?"
Just a thought, and hopefully something to think about.
I'd recommend coming up with some simple question you can ask her, like "Hey, my friend said you worked really well on that last assignment, do you think you could give me some ideas on ______?" (insert whatever topic you've decided on) Frankly it can be anything from music, school assignments or whatever. The point is to get past the part where the two of you haven't talked about anything. Coming up with some simple question, then asking her specifically, gives her a chance to talk to you about something that avoids whether you like her, or she likes you, and yet shows that you are interested enough to go out of your way to ask her opinion. It also allows you to be friendly, without having the pressure of asking her out on a date, before you even know each other.
I think you will probably enjoy how easy it is to go from something as simple as "Hey, what did you get as the answer to problem #3 on the math assignment?" to "Thanks, I wasn't sure I got that right... Say, are you doing anything after school? I was thinking of going to get a sundae at that ice cream place downtown. You want to come with?"... And from there, you're in a position to let things go where they will.
Just don't act too cool, or she may think you're just teasing her. Be open, honest and casual, and see where things go. You'll be just fine. And remember: A casual offer to go for a sundae, or some fries, or even just a soda, lets you have to freedom to say "Nah, that's ok, I just figured I could repay you for helping me out, it's no big thing." ... In the event you get shot down, and she's not as interested as you think... It's just a simple way to open the door for her to talk to you, and then let her make the decision if that's a door she wants to walk through...
Hope this helps, and good luck. Oh, and if this does help, remember to rate this answer appropriately. Thanks.