Why not talk to them about what quilting is, showing several simple patterns and asking what they would like to do. Jelly rolls and charm quilts may make life easier. what is their goal? Teach them safety of rotary cutting, how to use a ruler, etc. Just have them do one block and bring it back in for discussion. Tell them to use inexpensive material to practice. After that they may want to do more creative pieces.
Good luck.