She also talks about being 5 or 6 and in the Bahamas with her family at some hippie resort. The parents neglected the two kids for days at a time. The two kids would wander around and get fed and bathed by random families who felt pity for them.
She also talks about being around 14 or 15 and living in the hills just above the Sunset Strip. Her parents go to London and end up staying. They sell the hollywood house out from under Mac and her brother and just abandom them. Mac makes her way down to the strip and ends up meeting Fred Roos at the Central (now the viper room) who casts her in American Grafitti.