Those look good ideas. Problably I'll try more than one approach to see what they like and to learn a little bit more. Thanks for advices.
Today I start working in my model again. I followed in general lines the famous and spectacular Joan of Arc's tutorial by Michel Roger (https://www.3dtotal.com/ffa/tutorials...c/joanmenu.asp). I think my model is getting better now, she's more what I had in mind. Let's see if she will look a woman this time
Here's the sketch of her back,