Breh, you kidding?
When she was 13 she saw her stepmom's mom suck Roger's dikk and not long after that caught Don laying down the pipe to the neighbor. She was already lashing out in boarding school.
By the end of the series Betty basically tells her in the most Betty way possible that she loves and that she better be ready for what's to come and Sally ends up as the de-facto housewife while Betty lives her last days
When Sally is 17-20 she would be riding the disco cocaine fukkery right through the 80's