Should I ask a girl whats wrong?

Nah it's not that deep, you should ask if you feel that she's airing you for no reason.

Next time I see her I was planning to strike up a convo but I just feel like shes blanking/avoiding/ignoring me. She is quite shy so when its busy shes more reserved. It is something thats playing on my mind so I need to sort it.

This is how I envisage that conversation going:-

You walk up to her, and she's still sulking

You:- Hi *NAME* I noticed you've been really off with me lately, what's wrong?

Her:- Nothing, I'm fine!

You:- Clearly you're not, you've been blanking me, and ignoring my texts, seriously, what's the matter?

Her:- Well if you can't work it out, I'm not going to tell you.


She then storms off.

That's how many women work in these kind of scenarios, you're never going to get a straight answer from her. You'd be far better off trying to talk to her bestie and see if they can give you any clues to what you have / haven't done. Also, think back to the last real interaction you had with her... is there anything that can be taken ambiguously? Did she catch you doing something you shouldn't? Did you flirt with her mate?