Bold and brave drawing! It has style and life. It was a fun drawing, and reflect the joy of the subjects.
My grandfather would have told you not to scribble, but to make your lines purposeful and disciplined. Make each line count, and make it espressive. Discipline should give way to expression, however. Perhaps your features could be a bit more defined. It is OK to be a bit abstract around the edges, but the features need to be more carefully defined. Watch the eye axis. The drawing however is delightful!
Well done.