I used Brazil for rendering, here's an image of the material I used for the skin.
Rigging
I used bones to rig her. I was not planning to animate her, but I wanted to be able to pose her well, so I did a simple IK arms and legs, as there was no need of an Fk/Ik solution just for posing.
The only special thing I did was using bones to rig the hair too. I had around 50 different hair objects. I grouped them in 6 zones, and I used a spline Ik for each of those zones, so I was able to move the hair without having too many controls. I did the skinning of the body, and used skin wrap on the clothes to make them move with the body. The image where she is taking her t-shirt off was special, as I was not using any kind of cloth simulation, so I had to remodel part of the t-shirt in that pose to make it natural.
Being a cartoon character, the facial animation was very important to make her credible and to bring her to life, so I spent some time on it. I used morph targets for it, making several different morphs for each zone and having left and right sides in different morphs, even for the mouth, so I could easily create some asymmetry on her face combining some of them to create each expression. Eye lids are also movable using a morph target that is linked to the eye morph, so when I move one of them, both are moved.
Here are a few final renders: