An anime fan eh? These are quite well done, the first and the third one look almost like they were done by a professional. I'm curious, has she practiced drawing realism yet?
Gotcha. I ask because around age ten is when most young people transition to realism drawing. It is also where most young people give up on art, because realism is particularly difficult; you need to develop an artists' perception to do it, which she seems to have done. Realism is important for advancing your skills as an artist and finding your own style, and something she'll be doing much more of if she decides to pursue art classes. Drawing cartoons and anime is great, and she most certainly should continue to if that's what interests her. But practicing realism is where you'll see most of your improvement, which will help improve her other style drawings as well, so don't forget to practice it in between other projects. Anywho, the works you have posted here are great, and if she continues with it I have no doubt she could become an accomplished artist some day.
MIKE!!! I LOVE YOUR SISTER EVEN MOAR! SHE PUTS TROLLFACES ON YOUR DOOR DRAWS PONIES AND NOW DRAWS EVEN MORE AWESOMENESS?? HOLYCRAP WHY IS YOUR SITER NOT ON EVERYPONY DUDE!!!!!! I will say this only once: Your sister is better than you.
Your sister did that? WHOOOOAAAH!!! They seem professional. The first two seem very real like. Hatsune Miku? Awsome.