I think she likes me but I don't like her in return. What to do?

[Jack]

It wasn't long after we left high school, and I was a bit down in the dumps because of it and posted it on twitter. We had never spoke about it, and she messaged me and asked me if I was alright.

It's 3/4 months since then, and she talks to me on Facebook everyday since then. And if I don't reply to a message of hers it's always she messages me asking why I'm not replying and such as.

But this is the bit which makes me think she likes me. I've always fancied my best mate's sister, but it isn't often I see the two. But I was with them near the end of July this year, and I was messaging her about how I liked this other girl. Not so long after, she posts these two tweets.

1. "I get jealous way too easy"
2. "That should be me. Not her.

The fact she tweeted those two tweets, and that she talks to me 24/7 makes me think she likes me. She also asks me every now and then if we would ever go further than friends, and if I say to her "Well, maybe not" she will go "Good" and will not admit she likes me so she might not either but I don't know.
Even now. She's stopped on at school for the next two years whereas I'm going to college for a fresh start. I start Monday 17th, she started Sixth form this Wednesday. But she's sneaking on her phone while she is meant to be studying just so she can talk to me. She says she is talking to others too but I don't know.

So do you think she likes me? And if she was to admit she liked me, how do I tell her I don't like her in a polite way? Help!
By the way, I don't know if those tweets were aimed at me, she claims they weren't but I don't know

[Ben]

Yeah she definitely fancies you mate, no two ways about it! As for what to do....keep on doing what you're doing, don't answer every msge she sends as that just encourages her, if she asks why you don't reply just say something along the lines of "look i'm really sorry but i think you may have got the wrong idea, i like you as a friend but nothing more"..........chances are she might get a bit upset but you can't take responsibility for other people's feelings

[grownup]

How could you ever have any kind of relationship with someone on a piece of equipment? You're like robots talking to each other. Very immature.

[Sophie]

She sounds like she likes you, coming from a girls perspective..
Dont say anything to her until she approaches you about it, because if she doesnt your going to sound like a bit of a tool
Just carry on with what your doing, try no to lead her on when your talking to her with pet names like 'babe' and such, tal to her like shes one of the lads and she should get the message
If she doesnt just tell her straight that you dont lie her, may be harsh but that beats tearing her down bit by bit.. you dont want to be that kind of guy

[Shweta]

U need to tell her that u don't have any feeling for her except good friends

[Phoebe]

Sounds like she definately likes you, just let her down easy and say that your not looking for a relationship right now. See what happens