Hi Alex, I am glad that you are documenting the process of learning the art mediums of your children. It is very interesting when kids starting to experiment and capturing them on photo make it easy to see how they change their technique, how their skills get better too. I see that your son has little size brush. For watercolor it is better to use bigger sizes of brush because they can hold more water and the strokes can be more random. Maybe something to consider for X-mas present? Thank you for this beautiful painting :)