Chelsea Singh is a Vulcan, a direct descendant of Spock see below
Chelsea's great-grandfather is depicted below
When a war erupted between the Delta and the Alpha Quadrant, the Vulcan race was almost wiped out. Only a few survivors managed to find refuge and were scattered through the universe.
The House of Spock managed to survive on Earth where living conditions were similar to those on Vulcan.
Over generations, Vulcans adapted and became more and more like Earthlings. Gone are the characteristic pointed ears and the stoic logic and lack of emotions, though the hairstyle had to remain, to distinguish the Vulcans from all other races on Earth. Indeed, akin to the distinguished hairstyle of the Sikh.
As it was deemed by the Vulcans that the Sikh were most understanding to their plight on earth, they decided to pay homage in the form of integrating into Sikh society, hence Chelsea's surname Singh.
A few more generations into our time, the vulcan Singhs decided to migrate to the British isles where they established a thriving business that soon earned them abundant wealth.
The Singhs then realised that they had to at least make a token gesture of integrating into the British way of life and this is when it was decided that the first-born son should be named Chelsea.
Below then, an image of Chelsea Singh

