some more advice, please

Some more advice would be appreciated,
continuation of: loveforum (dot) net/love-advice-forum/58476-some-advice-would-greatly-appreciated.html

So yea I know I said I was gonna ask her out and stuff but I havent got the chance to meet her in person yet though I will next week. Anyway but after a bit of thinking I thought that it still wasn't time to ask her yet but it is getting closer.

Well I have never had relationships problems until now. Maybe because every girl I considered asking out gave me clear indications that they liked me (and maybe that is why relationships I've been in lasted more than the average relationship) so it wasn't a problem for me to ask them out.

But with this girl,I feel I actually have to make too much of an effort to even talk (she does talk to me when she needs help and Im the first before she asks >.>) to her but she still shows me signs she likes me with confuses my brain as to which strand to follow.

I feel she is either playing a game with me (or if not with me with someone else she likes)... well she went from being in a relationship to being somewhat depressed now she is kissing a different guy every night (which is very unlike her). I suggest you read the other post to get a better idea.

Also I have noticed from this month a new trend when I talk to her, before she used to answer me instantly now she takes her time or sometimes even ignores me completly (ofc she might be busy) but she might be trying a test. This is gonna seem paranoid (amongst other things)... why do I think this... cause I tried to do the same thing XD ... and Im slowly starting to realize how similar we are/think, before it was just we said the same exact jokes or gave the same exact answer to a question... which left me speechless.

One thing I forgot to mention is another test I tried which at the moment seemed significant. I went 30 minutes late to class just to see how she would respond, while all the rest of my friends just looked at me and looked away she looked at me up and down twice before she turned away.

Another problem I've come to realize recently is how uncomfortable I am flirting with her. Some people call making fun at each other or joke around as flirting but I dont beleive it to be the case. Problem I have with flirting is it use it sooo much to get girls to do me fancy stuff that when it comes to flirt with a girl I really like it almost feels cheap (unless I know she likes me)

Also another point I would like to quickly add is that she refers to me and her as if we are best friends but we dont talk that much which also seems odd to me but I do understand her cause I do the same thing. Also a month after I met her she had her birthday, and she tried her absolute hardest to get me to go... but I couldnt cause I was still 2months under age :'( and couldnt risk getting caught drinking up age at that time.

Anyway guys I need some serious advice of what I should do next. I have gut feeling (gut feelings have never let me down before) she does like me but is confused if I do like her cause I try not to make it too obvious like she might. But there needs to be another way to indirectly see how she feels without having to go all in ... cause I dont want to create any awkward situations. People your help would be greatly appreciated, thanks <and thanks for reading all this>