Right here goes...

I met a girl a few weeks ago through some friends and we seem to be getting on really well she seemed really keen when I have been with her, we have been out for a few drinks a couple of times and she's really good friends with my step sister who hasn't told me anything bad, so I'm presuming that I may be in with a chance with this girl anyway here is the problem I have to contact her all the time to see her again I text her asking if she wants do do summit then we do... then I text her again and she replies etc etc but she does not seem to contact me at all I could leave it for days and hear nothing then when I contact her she seems up for doing stuff again!!

Help please :)

It sounds as though she does like you since she is at least spending time with you. I see this in three ways:
She is to shy to call you and ask you out.
She likes you and enjoys time with you but not enough to go out of her way to make the plans.
Or maybe she is just being polite hoping you will back off on your own.

Why don't you just ask her about this. Ask her if you're an item or if your too much and you should back down. Or let her plan the next date and see what happens from there. If she doesn't plan one then there is your answer.

Enlighten me lol

If you are interested in getting involved with this girl I would be cautious. Unless you want a quick relationship, it takes 2 people to do the work- not only does she have to work at the relationship, she has to meet you halfway. This girl is already slacking off when it comes to putting forth some effort- right now, it doesn't seem like she's worth looking into.