Preeti is a character mentioned and featured in some of Lilly Singh's early YouTube videos. She is a relative of Lilly and Paramjeet is constantly comparing her to 'successful' Preeti, when in reality Preeti is an alcoholic who wears dresses 'made of saran wrap'. Preeti is around the same age as Lilly.
It is mentioned that Preeti attends Med School, but it is unknown whether this fact is true. She most likely lives in North America; specifically, Toronto, as this location is where Lilly has filmed the majority of her videos.
Rani Aunty often confuses Lilly with Preeti (and presumably vice-versa), so it is presumed they look similar and are around the same age. Paramjeet also commonly compares her daughter to Preeti.