Improper body alignment during handwriting can limit proper function and independence. Here are some tips of things that you can do at home to help.
During seated tasks of writing, painting, etc..
Use a 3 ring binder or slant board as a writing surface to promote proper wrist extension to a more functional position.
Use smaller writing utensils (small pieces of chalk, golf pencils, etc) to force a more desirable tripod pencil grasp.
Make sure paper position follows the slant of the forearm being used for writing, and is placed at the midline of the work surface.