My[17M] friend [17F] broke up our friendship after I didn't pay her 5 bucks that I "owed" her (I didn't)

tl;dr: Friend tried to convince me I owed her money that I didn't. When I refused, she started offending me, blocked me and is now **** talking me
Sorry for any mistakes, I'm on mobile. Also, the currency isn't actually dollars but the values are so small I won't bother converting it.
The title sounds a little ridiculous, but I'm not sure how to proceed in this situation, since I've never had a friendship end without it being amicably.
So, this girl, which I'll call Jane, is the girlfriend of a friend of mine that moved away and we've know each other for at least 4 years. As a bit of backstory, we argued a lot last month because of a school project which she thought I didn't contribute enough (she was the only member of the group to think that).
When the school announced we would be having a "fair" (each class gets a topic, makes some posters and **** and we assemble at the gym on a Saturday to present it), I said to my friends A,B and C (they'll be relevant later) I didn't want Jane in the group because she took those projects way too seriously (she has bad grades and tries to compensate it, I think) and it wouldn't end well. She got offended and my friends decided she would be in our group after all.
Now, this project envolves a lot of aesthetic/artsy work, which I'm absolutely useless at, so I mostly did some minor research work. There were a lot of comments from her part about me not doing anything, which I didn't reply back because I wasn't doing much, since I didn't want to ruin anything.
Along the project we had to buy a few itens: I spent 10 bucks on some paint, friend A spent 10 bucks on a map and Jane spent 15 bucks to reveal some photos. Friend B gave me 2 bucks (his part of the 10 bucks I spent), friend A didn't pay me and I didn't pay him since the debts nullified each other and friend C didn't pay anything but we used his car so he spent it on gas. This is a bit confusing, but it's important.
Last night Jane messaged me saying I owed her 5 bucks and to bring it tomorrow to school. I asked why and she said it was for the photos she revealed. I told her I would pay her 3 dollars (since it was 15 and we are 5), she got mad and said "**** you, just pay me". She then said that her and friend A didn't need to pay because they already had bought the supplies (including a "WTF I HAD TO GO THERE WHILE U DID NOTHING"). I said that no one but friend B paid for my paint, she then lied and said she paid for it (I asked my friends in case I forgot that she paid, but she actually didn't) and then sent an audio with a almost-crying voice saying telling me to just pay her and that it was her lunch money for this week.
When I denied again and explained why I didn't owe the 5 bucks, she started offending me, saying things like "you're a ****ty, toxic and person" and "that's why you'll never have a real friend" and when I said that if she needed the money so much as to offend me for it she could have just asked, she blocked me.
Today she started **** talking me to other people. 2 other girls (peripheral friends of sorts) came to me to ask what happened. From what I can tell, they thought she was in the wrong too.
What the **** do I do? I don't really care about the money but the fact that she tried to manipulate me, lied and then started offending me for no reason makes me want to never talk to her again. I share all my classes with her (different system, I'm not american) so it's not like I can avoid her completely and I don't like the idea of spending my remaining 3 months in school in this situation. I'm not really mad, just extremely disappointed that someone I trusted would try to pull this **** on me.
edit: forgot to mention, she did this with friends B and C, but they just paid because they didn't want to deal with it.


Source.

That's what this whole BS post is about, she DID ask you for it and you being a cheap lazy basta.rd not wanting to do your part, by your own admittance, won't give her $5 little dollars.

WTF did I just read?