First of all, i am literally listening to 'Words Fail' from DEH at the moment which was quite ironic.

Secondly, I apologize in advance for how bad I am at giving advice, but I shall attempt it.

Do you two have any mutual friends? If so, try to hang out with her in a group, that way you should hopefully be a bit more comfortable.

If not, possibly try to find out if you two have any mutual interests. When I had a crush on a girl in my neighborhood, I asked her sister what kind of stuff she liked, and found out we both love Voltron. From there, I was able to converse with her via a topic very special to me, making me much more comfortable and confident. 

Sorry if this was all a mess or not good. I did warn you.

I hope everything goes well!

Oh my Zeus,

Here she goes. 

Talk to her. Say hi the next time you see her, then later introduce yourself and/or give her a compliment (ex: I like your hair) (she'll probably tell you her name after you tell her yours if there's a pause, and say thanks after the compliment, to which you should reply with you're welcome and then either leave or allow the conversation to continue) whenever you're ready, or a week after the first 'hi' if you're not getting any closer to ready by that time.

Once you start seeing her as more (or less, as it were) than a goddess, the butterflies will get easier to control. Also, it's probably going to be very obvious that you like her. Don't worry too much; most girls would be flattered to some extent (perhaps a little weirded out by the age difference, depending, but flattered), and if she's mean about it, she's probably not a girl you would want to get into a relationship with.

She'll be aware that you are not your brother and therefore aren't automatically someone she'll dislike. She might be skittish about potentially spending time with your brother, but probably not about being around you.

Oh yeah, I think you can trust me on this. A younger boy once had a crush on me (one of two times I remember when a boy told me they liked me), and although I wasn't interested, it was sweet. (Claaws, it feels weird to open up about that though)

After you start talking to her, as you hopefully will, find a way to spend some time with her. At least, if your goal is a relationship with her... A kind of courtly love or distant adoration is also acceptable, but not what this advice is good for. If you want to crush from afar, just keep doing whatever you're doing. A note, though: Staring is creepy. So is finding out her schedule and going where she goes so that you can watch her. Don't do that. Asking people about her is also creepy, but a lot less so if the people know you have a crush on her. Writing about her is cute. Singing outside her window is over-the-top romantic.

Anyway, where was I? Ah yes, interaction. This will probably occur some time after the first conversation. She might not ask, so you should be prepared to. You can try hanging out with others at the same time as with her, or just go for alone together right away. Games and homework are good activities. Also parties. And maybe food? I'm not sure why dinner dates exist, but then again I prefer to eat alone, and I'm weird. 

Confess your crush to her around this point. Doing so before you first hang out will give her a better idea of why you want to spend time with her and why you're awkward around her, and after will let you get to know each other outside of that context, and also keep her in your life while you stall/work up the nerve/figure out how/wait for the perfect moment. After you confess, she'll most likely tell you how she feels about it. Which, as you may recall, is probably flattered. And then if she likes you back, you can continue to spend time with her and eventually go on to the dating part.

Hope this helps!

...How did you not melt into a puddle of squealing goo.

Magic.

It must be.

Of course, I've got shoujo bubbles crowding into the space behind my sternum and collarbone, but giving advice requires rational thought, causing them to subside. But that part's done now. 

Oh no.

Zeus and Hera, Nymph! Mythology! Hera was older than Zeus, but they got married and also Zeus! Let's call mystery crush girl Hera, or actually mythological Zeus had a lot of loves... His first was possibly a nymph and the mother of Athena. Hmm... 

...This isn't as bad as usual.

It's real. It's different. I think Hera is as good a pseudonym as any for our unknown lady, don't you?

*wanders off without reply* 

Wow, hi, Zeus! I haven't seen you in forever! Ok, so I have absolutely no expirience in liking people, much less talking to them, but I'll do my best to be helpful. That being said, please take all this advice with many grains of salt.

Can you try talking to her about something? Ask about a book she's reading or tell her you like her shirt. Do you know any interests you have in common? Maybe she likes musicals too. You could get into a conversation about that. I'm not sure how you'd apply this, people like talking about themselves. Act interested in her likes and dislikes. Not to the point of nosiness or creepiness, of course, but people like when you care about their opinions, I think. Again, I'm definately not an expert in crushing or human interaction, but I think these are good ways to get started. Once you start talking more I'm sure she'll see what an interesting, cool person you are, and I'm sure she won't hold your relations against you. You're different from your brother and she knows that. Good luck, Zeus! I believe in you!

Wow. Thank you all.

(Future readers, don't be discouraged from also giving advice; I need as much as I can get.)

For the record, I do actually know her name, and I might as well write it here because you guys know pretty much nothing about me that could identify me or her in real life and also because I kind of hate Hera in the Greek myths so it's not my choice of pseudonym.

Um. Okay. Sorry about that run-on sentence. Her name is Jane. And she does like musicals and a lot of similar things to me.

I didn't see her today, but on Monday I will do my best to apply the advice I've been given so far and hopefully not look as stupid as I usually do around her.

As for telling her, that would be a long, long time from now if ever. So... anyway...

Thanks for all the advice. Thanks in advance for any more advice. I am very grateful to you all. 

I sort of have no clue what I'm saying and am not qualified to advise you seeing as how whenever I have crushes I get incredibly freaked out BUT

I would say, behave towards her the way you would to someone you want to become friends with. Try to imagine what you would do if you wanted to get to know her better for non-crush reasons, then do that. Because it's usually easier to have good when you aren't clouded by having a crush. So imagine you didn't have a crush and think about how you usually make friends. 

Hope that helps. I know crushes are usually totally outside of the friend-world and in some strange alternate crush-world, but I thought it might be a good idea. 

I don't know how many of the people that commented on here are also boys (none so far I don't think, if you are then please excuse me), but I know it can sometimes feel awkward to be younger than a girl when asking her out/ telling your feelings. It shouldn't be that way, but our society has forced it to be. All I can say to you, Zeus, is don't let that stand in your way. Like everyone has been saying, find some common interests or mutual friends. Maybe ask her for book recommendations (or something like that, I'm probably old fashioned).

Hope this helps! I'll do anything for a brother or sister in need.