The unnamed relative was out with pals when someone laced her drink with a drug that knocked her out for three hours. Friends had to sit with the 20 year old in a room to make sure no harm came to her while she was out for the count.
Pinkett Smith tells Wenn, "Thank God nothing happened because she was with some responsible guys that took care of her and with three of her friends. She was saved because she was with her friends.
"She started losing consciousness, and immediately the people that she was with put her into a room, closed the door and got the other girl there - and kept her there. She didn't come to for three and a half hours.
"She's doing fantastic. Thank goodness nothing happened and it was a big lesson for her."
Rather than try to sweep the scary incident under the carpet and forget about it, Pinkett Smith decided to use it as a life lesson for her teenage daughter, Willow.
She adds, "I had my niece sit down with my daughter and a couple of her friends and tell her about that experience. I don't just sit with Willow and go, 'Hey, this is what mummy thinks', I just bring in for her a little reality to validate what mummy's been talking about.
"When you have your 20-year-old cousin come in and she's like, 'This is what happens...', and she's someone that you look up to as well; she's like, 'Oh man, this is really real. Let me pay attention'. Then she can kind of mesh the information that I've been giving her and the information her father's been giving her, her brothers have been giving her, with the truth of this reality - of how this event actually touched our lives...
"She welcomes that kind of information and she welcomes when she can have more truth too. If you allow a person to be an individual and have power within and have confidence on who they are, she'll never have to look into the eyes of a man and question whether it's a 'yes' or a 'no'. She's gonna be very clear and she's gonna be in a position to determine how to protect herself and know when she's in danger. Should you be a girl that goes into a room with four men drinking? Should you? Even if you think you know them. Is this about wanting to be the cool girl? Or is this about wanting to set a standard for yourself?"