Wait a minute...the reason they fight and she acts the way she does is because he doesn't remember her, but she remembered him very clearly?
I get it, being asked who you are by someone who you were interested in and was important hurts, but she still could have acted a little less...fiery, to say the least. She could have easily cleared things up by just telling him who she was when she walked up to him and while she may not realize it he would have remembered her...she isn't that forgetful.
To be fair to him she does look different than she did when she was younger, so I can see why he would not recognize her.
Ugh these two...I mean really. They both have made it clear that they were each other's first love, him more so because he keeps bringing up that girl he met (her) and this chapter we find out she was in love with him at the time. She most likely still is in love with him but she just CANNOT be honest with herself or even talk about this stupid misunderstanding to get over it so instead she just keeps taking jabs.