The Redstone family is feudin’ again.

Keryn Redstone, the granddaughter of Sumner Redstone, the controlling shareholder of both Viacom and CBS, is supporting the mogul’s former girlfriend, who is battling to be reinstated as health care agent to the ailing 92-year-old mogul.

Keryn Redstone is asking to join former galpal Manuela Herzer in her attempt to take charge of the billionaire’s healthcare, according to The Hollywood Reporter.

Sumner’s daughter, Shari Redstone, was close to a deal to take charge of her father’s health-care decision-making, but that preliminary agreement fell apart.

Keryn is the daughter of Brent Redstone, Sumner Redstone’s estranged son.