A soul mate is a person you knew from past lives and were together with or a person you can be very close too cause of being the same nature.
Probably not everyone has one from the past or will find one in this life. If you both were Zevism in past lives its highly likely you incarnate at the same time and plan it out so you will find eachother. Not everyone has a soul mate i guess but you will remember her most likely if you do.