Nerys Myk wrote:
Though the question remains, why did Marla think he was Sikh? Did she know he was Khan?
The real-life answer: the costume, makeup, and hair departments didn't do their homework about Sikhs and so the character's look didn't fit the script. It's typical of '60s TV portrayals of Asia that they wouldn't have cared much about accuracy or authenticity.
In-story, yeah, maybe Marla suspected who he was and kept quiet. She was a student of such dictators and had kind of a fetish about them.