For a cartoon, I think it's great. It definitely portrays the fact that she wears oversized clothing. I think the character is interesting because she seems outside the "norm". The drawing itself is okay. The color/shading is great, but I think there are some issues with perspective (the shoes) that could be worked on to give the character a more realistic feel. I wouldn't actually get the impression that she's supposed to be "fat". The face/neck seems to portray older age, rather than weight. I think you have a good basis for a character, though.
All in all, I'd honestly like to see the comic she's in and the character development you give her!
All in all, I'd honestly like to see the comic she's in and the character development you give her!