The marriage collapsed permanently in 1977. When Bonnie Poorman filed for divorce, Amber was just five years old. What followed was a protracted, agonizing custody battle that set the tone for the rest of Amber's life. Bonnie fought fiercely for full physical custody, presenting evidence of Vincent's worsening alcohol dependence and unpredictable behavior.
The court ultimately awarded full custody to Poorman, granting Vincent visitation rights that grew increasingly erratic. Rather than lingering in the orbit of Los Angeles soundstages, Poorman made a deliberate effort to insulate her young daughter from the film industry. She raised Amber away from red carpets, studio lots, and celebrity culture. While Vincent's star climbed toward its commercial peak with the 1978 surf classic Big Wednesday, his actual involvement in Amber's day-to-day upbringing steadily evaporated.