Dolly Parton and her siblings are in a legal fight to gain control over their 77-year-old mother's affairs, reports The Knoxville News-Sentinel. The country star and nine brothers and sisters filed a lawsuit in November in Sevier County, Tenn., seeking to have Avie Parton declared incompetent so one of them could be appointed to oversee her $1 million estate. They claim she is showing signs of dementia. However, Parton's mother contends she is capable of managing her own life and finances. Two of Dolly's siblings -- twins Freida and Floyd -- have sided with their mother in the court battle. A trial date is expected to be set for later this year. Parton's father died just days after the lawsuit was filed. Parton honored her mother's love in her 1971 signature song "Coat of Many Colors."