Portrait Painting For A Week and A Half

I have jumped back into painting portraits. I am taking a class and then showing up for open studio with a live model.
In class, I asked for help with the portraits from the instructor, Debbie. She expertly showed me how to improve the studies. It was an excellent lesson in both cases.
So,here is the past week and half studies.
The first study, with the green head scarf, you can see where I mixed too dark a color for the jaw. I struggled with the nose and Debbie demonstrated how to correct it.
The painting with the dark skin model was improved with highlights.
The last painting is from the open studio without instruction. I put the models heads too far down the canvas. I struggle with the hair and need to learn how to paint it more effectively.
Great lessons. Oh and if I haven't said it before, the more you learn with art, the more you realize you don't know.