She said i was "irrelevant" if that's the case why does she want to be my friend again.?

[wazzzzup]

Ever since last year i had befriended this girl. She was so quiet , never really spoke or saw her around much people but that didn't matter because i was willing to be friends with anybody. When i added her on facebook she seemed to have alot of friends so i guess only in school she kept to herself.

The other day her and i had gotten into argument and she called me "immature" and "irrelevant" just because i had asked her advice (as friends normally do) then the reality hit me. She was always a sucky friend. When people are suppose to meet you halfway (50-50) she didn't meet me anywhere near that. She's the kind of friend who you would do things for that she would never do for you.

Few examples.
We went out to eat one day at applebees. Ironically she forgot she didn't have money exactly when the bill came and i paid the entire thing ($52) next day at McDonalds after school i asked her to get me a french fries and she had about $20 it was too expensive she said.

I traveled all the way from another borough (2 trains and a bus about an hour and a half and she wouldn't walk out her house which was 5 minutes away)

I waited for her at the library for an hour and she didn't come. Next day we decided to meet again and she left after 5 minutes literally.

All of that hit me after our argument but now she wants to be friends again. I thought i was "irrelevant" what does she need me for ?