Hey there.
I might be able to help, I'm kinda new to this too, so by no means take my advice as word, but Il try my best
You sound a bit cold when talking to her, like you "cant be bothered". Playing hard to get is good, but you CANT be impossible. You have to show signs of interest too, its all about the combination of interest and disinterest, if you get what i mean.
Eg.
"Her:HEYYYY do we bring in all our work tomorow?
ME: lol, keep up! are you always this forgetful?"
Straight away, make her qualify herself wit a lil neg in there for good measure.
"Her:ohhhhhhhhhhhhhhhh i am getting so confused!
i need to write this on my calender
lol...everyone getting confused, ur the fifthd person that ask me this.
hahahah i have like 200 things crossed out on my calender
so we are off the 22 and 23?
Me: No idea! your the one with a Calender

"
If I were in this situation, id feel a bit bummed that she came on purely to talk to ask me whether some work was in or some crap..
Remember that online, there is literally NO body language, which is very super important in talking to women, try to get an element of body language in there with the use of sentence structure and smiles n stuff. Also, I think women like being teased, and you have to play the right tactic, remember your not there to be their friend (to a certain extent).
Would be good if any more experienced PUA could expand on this. Like I said, i'm just trying to put this stuff into practice too.
Cheers.