Sure. Slovak was taught by a mother and daughter team. The daughter knew the most about language pedagogy because she was able to attend our training sessions, and the mother knew the Slovak language best as she lived in the area of the former Czechoslovakia where that language was spoken. They complemented each other.
Another example of ³family² teaching would involve Samuel and Aristide Ze, who are identical twins from Cameroun. They taught Boulou. Imagine a class of Boulou presented by identical twins--a foreign language in stereo!