I second what Sarah said. It goes back to the perspective of Charlotte’s method. Your oldest being just 6 shouldn’t need an expensive curriculum. Now I learned to draw and then paint watercolors of our children by just practicing and learning to ‘see’, and I have watched our children do likewise. And like Sarah said, nature studies is the way to keep at it. They find something outside, bring it in, and go to a table set up with watercolor pencils or simple paints and pencils. We keep ours set up and my 10 children at home draw and paint 4 times a week at a learning station. The key is to paint something in front of you. That way you learn to see it’s shadows and textures, and to mix the color just right.
Also agreeing with Sarah about picture study, which inspires us all to ‘do likewise’. I know the urge to go and buy is strong in all of us–but honesty, Charlotte said to have faith in the minds of our children. They are truly amazing. Fact is, a dvd or book can help, but doesn’t it really boil down to us taking time to really look and often practice that makes us improve on that skill? Now when your children get much older, and if they excel in this area that would be a good time to get the instruction books and take the art classes.
From Vol. 1 “Children of six and seven draw budding twigs of oak and ash, beech and larch, with such tender fidelity to colour, tone, and gesture, that the crude little drawings are in themselves things of beauty. Children have ‘Art’ in them.––With art, as with so many other things in a child, we must believe that it is there, or we shall never find it.” Read on my friend, here, scrolling down to page 313.