sketch of anime girl

ok..well on wednesdays i do tennis as a sport and only half the time you're actually on the court.. i got bored so one of my friends gave me a picture she liked and asked me to sketch it. so i did...it took me i dunno 3 or 4 times doing tennis..(it's something like that...i think...) anyway since then i'v found out who the origional artist was. maxwindy! a really great artist!! anyway i have her permission now...here's her picture [link]
go have a look and prepare to be blown away!!! it's SOOO much better than mine (not that that's hard..lol)

by the way i sketch anime to learn how to draw it..and to learn how to do the shading..it's much easier than trying to draw with no idea how to!!! anyway i'll be sketching untill i know how to draw anime and when i am confident enought to do origional art..lol i'm quite far away from that point though..

constructive critisism appreciated!!