I have the fondest memories of Jan from my earliest days on the scene in 1975,when I arrived at Karme Choling in a confused haze of pseudo-Marxist bolshieness -- a term she'd know -- and monkish celibacy, vegetarianism, etc. Then she could indeed manifest Thatcherian toughness when keeping me in line -- but always with a warmth and twinkle there somewhere.
One day I shame-facedly asked her to put me on the list of people going to the St. Johnsbury Clinic to be tested for a sexually-transmitted disease rampant at KCL the time. She responded with the most glowing and genuine smile and in her poshest English accent said "Congratulations!"
Bon voyage, dear Jan