I think you are on the right track with your thoughts on how to teach your friend braille. The American Printing House for the Blind has a device that you may have used as a child.
Swing Cell Compact
Similar to the Swing Cell, but without the base. Smaller and lighter than the original. Helps students understand the relationship between the braille cell and the keys on a braillewriter. Internal storage of pegs. Recommended Ages: 5 years and older.
Swing Cell Compact:
Catalog Number: 6-78041-00
Click this link to purchase a Swing Cell Compact.
American Printing House for the Blind, Inc.
1839 Frankfort Avenue
Mailing Address: P.O. Box 6085
Louisville, Kentucky 40206-0085
Toll Free: 800-223-1839
Web site: http://www.aph.org
APH Shopping Home: http://shop.aph.org