Now I can't do much an advice, but I'm a chick and a little bit of a special case. I hung out with a lot of guys in high school, but I considered it all friendzone. It got really fekking awkward when one of the blimeys got drunk and asked me out while walking me home from the public park in which he got drunk. Lesson: Be careful of the cockblocking friendzone, it's a killer.
Now, make sure you're actually reading her actions right, because men do tend to think ladies are flirting when they really aren't, they're just trying to be courteous. Since she said she actually likes you though, I assume that's not a problem. I don't know about her, but I'm an oblivious cockblock to myself, and didn't realize a guy liked me until he straight up put his bleeding arm around me in the movie theatre. Which is great, because I am quite attracted to him as well. Sometimes, it takes the obvious moves to make us gals realize that a guy is into us as well, and because we're told that being the demure damsel in distress (Earliest 3D trend), making the first move is a little out of the usual for us.
Now, I recommend being upfront. Ask her: "Will you be my girlfriend," or some other cultural equivalent. Make your interest explicit. I'm not sure how exactly, but I can give my personal example: After the first date, as he was walking me to my door, I simply said "Look, if you want to go out with me, you have to come and have a family dinner with my father." Yessum. I'm that old-school. But that actually got him really excited. Seriously, I think he almost wet himself. The effect rubbed off on me too, and there was, of course, the million nervous goodbyes as I snuck into my door, and the racing thought of "Dayum, do I kiss him or not?". Went inside without doing so.
Flung my foot back and kicked my self immediately in the ass.
But it was all good, he actually came over the next day to meet my parents, and that's when we knew it was official. That night we were watching movies in my parent's house, and that was also my first kiss-- On my parent's couch, watching Edward Norton/ Tyler Durden get his ass kicked. (Fight Club, if you ask me, is a good geek-date movie.) I can't speak for all the ladies, but I think the first kiss demands just a little privacy.
AND THEN STEAMY HOT SEX. Just kidding.
That's the tale of my first boyfriend and first kiss. OP, I wish this all goes well for you. I can't speak for your girl specifically, but sometimes we like the man to take the reigns on the official status of the relationship. Making it clear that you're dating is the easier step, but I'm not so sure about the whole couple thing. By this point, my significant other and I have been called a couple quite a few times-- I think it might have to do with the variety of activities you two do together, such as whether or not you can both be in the same house and get work (school, job, otherwise) done, with the other around. Perhaps it's the question of whether or not you two are a functional unit when you are together. I don't know.
TBH, he's my first too, and we're at the three-months-and-a-bit-mark. To be fair, we're both first years in university, and he's got a few exes behind him. Just so's you know where all this babble is coming from.
tl;dr - Don't be afraid. Take the rains. Chickas like that. GL HF.