PHOENIX (AP) ― Dorothy McGuire Williamson, who teamed with sisters Christine and Phyllis for a string of hits in the 50s and 60s as the popular McGuire Sisters singing group, has died.

Williamson died Friday at her son’s home in the Phoenix suburb of Paradise Valley, daughter-in-law Karen Williamson said. She had Parkinson’s disease and age-related dementia.

The McGuire Sisters earned six gold records for hits including 1954’s “Sincerely” and 1957’s “Sugartime.” The sisters were known for their sweet harmonies and identical hairdos and outfits. 

They began singing together as children at their mother’s Ohio church and then performed at weddings and church revivals. They got their big break on the show “Arthur Godfrey’s Talent Scouts” in 1952 where they continued to perform for seven years.

The group made numerous appearances on television and toured into the late 1960s, making a last performance together on “The Ed Sullivan Show” in 1968. Dorothy stepped back to raise her two sons, Williamson said. Christine also raised a family while Phyllis pursued a solo career, according to a 1986 profile in People Magazine after the trio reunited and began doing nightclub and Las Vegas performances again.

The sisters last performed together in the mid-2000s, and are featured on a 2004 PBS show called “Magic Moments ― Best of 50s Pop.”

“They were a talent at a time when you had to have talent ― it couldn’t be done as it is now,” said Williamson, who is married to McGuire’s son, Rex. “Truly, their harmonies were some of the best and God-given and they always knew that and never took that for granted.”

The group performed for five presidents and Queen Elizabeth II of Great Britain.