I remember seeing this animated film (I remember it looking kind of like a Ghibli movie drawing style) on TV from 9 to 7 years ago, and it was all in colors. It was about a two girls, but one of the two is deadly sick and is about to die, the girl could have been on a wheelchair, but I don’t remember clearly. Not sure how, but the sick girl disappears and her friend goes to the woods where I think they spent time before and there she gets in this kind of fantasy world woods where some fantasy creatures have taken the girl. I think the sick girl and the creatures where friends, because they kept her there so that she would never die, because the moment she would have left the fantasy world she would have died. Her friend wants to get her out of there and the sick girl also woud like to, but they trap the friend. She somehow manages to escape and she brings the sick girl out of that world, and it ends with her dying.