I was watching Cheers on DVD and in the episode I watched I happened to see Diane's mother who was played by British actress Glenys John and I would like to know if Diane's mother appeared in any other episodes of Cheers? Also appearing in that same Cheers episode is a character named Boggs and he has a British accent and I would like to know more about him? Is Boggs the butler and driver of Diane's mother and does Boggs make appearences in other episodes too?
Bestie

No, they only appear in this one episode. Yes Boggs seemed to be Diane's mother's butler and driver.

Glynis Johns was in many movies, perhaps most famous for playing Mrs. Banks in Walt Disney's Mary Poppins.

Boggs made a brief 2nd appearance, in season 3 episode 1. He drove Diane home from Goldenbrook sanitarium.

Oh, good call, chips...I had completely forgotten about that. That's a nice little continuity there.