Girl likes me and wants to see me but won't commit to a date

So about 2 months ago, we matched on Tinder. The vibe was ok but it wasn't really going anywhere either. However, she messaged me on Sunday just gone saying sorry for not staying in touch. I admitted I could have made more of an effort too. We spoke more and she started getting more and more flirtatious. We spoke on the phone quite a lot and she said she really liked me, but also saying things like "you can do so much better than me", and "I think you're very impressive, I don't think I'll be good enough for you".

We originally had Friday night (tonight planned) but she didn't want to do it because she had work early in the next morning. She said she might be free Sunday. She said she might be babysitting, but is just being very non committal about it. "My sister doesn't know yet, should I just tell her I'm busy". I said "as long it's not going to bother her then yeah, let's do it".
I've given a very clear time place and location but she still hasn't confirmed. Thought she said she wants to see me and that she really likes me, but like I say just seems to be pretty non committal. She hasn't replied to my last text from last night and didn't answer my phone call. It's her day off today and I still haven't heard anything. Something just seems odd to me.

I'd be ok if she just said she's busy on Sunday and offered an alternative. She was out last on Wednesday night too (midnight) so that's bothering me a little bit.

My guts telling me to just leave it. What do you think ?