Katherine Jackson Ethan Miller/Getty Images Michael Jackson‘s mother Katherine Jackson has fired back at her grandson Bigi, amid their ongoing legal battle. Bigi, 22, (who is Jackson’s youngest son and previously known as Blanket) asked the court to block his grandmother from using her late son’s estate money for her legal expenses. According to court documents obtained by Us Weekly, Katherine, 93, is looking to use the estate money to pay for an ongoing legal battle. Bigi and Katherine initiall