Born in Melbourne, Australia, she told Carey that she and her family had lived in Hawaii until she moved to the Philadelphia region when she was 8.
A friend, Susan Johnson, wrote in recent biographical notes that Ms. Patterson's mother had sent her to live with an aunt in Flourtown.
"After being schooled at her Aunt Elsa's Carson [College] for Orphan Girls in Flourtown and the George School in Newtown, Bucks County, Yvonne left for New York in her late teens" to begin her ballet career.
When Ms. Patterson was 23, Johnson wrote, she was "first in line on opening day to try out for the newly formed School of American Ballet," directed by Balanchine.
"She was accepted as one of his original ballerinas and worked for most of her career with Balanchine."
The school opened in January 1934 with 32 pupils, its website states, and Balanchine used those students to begin choreographing his first ballet in America.
"She and . . . dancer and choreographer William Dollar were also original dancers in Balanchine's debut presentation of Serenade in 1934," Johnson wrote.
It was one of three ballets performed that June at an estate in White Plains, N.Y.
When she was 34, Ms. Patterson danced her "first solo in Constantia, which had its world premiere with the Ballet International in New York on Halloween 1944," Johnson wrote.
After she stopped performing in the 1950s, Ms. Patterson and Dollar "taught dance all over the world, working with dance companies in Brazil, Japan, Monte Carlo."
Until she was 95, Johnson said, she was a master instructor at the Rock School for Dance Education on the Avenue of the Arts, the successor to the School of the Pennsylvania Ballet.
Stephanie Spassoff, artistic director of the Rock School, is uncertain when Ms. Patterson began teaching, but said Ms. Patterson had taught her in 1984 when Spassoff was in the Pennsylvania Ballet.
Ms. Patterson had a kick well into her 90s.
This was how columnist Carey began his article about her:
"Yvonne Patterson has just divulged the secret to a long and healthy life - 'Movement: That's the key' - and now she's about to demonstrate.
"So down on her knees she goes, then flat on her belly on the Oriental carpet in her book-lined Flourtown living room.
" 'I do push-ups,' she explains. 'Though there's more push and not enough up.' "
Carey noted that "in keeping with her belief in the importance of movement, Patterson swims laps every morning at the Springfield Township High School pool."
"She's there every day at 7 a.m., except Saturday (when the pool is closed), and swims 20 laps, in various strokes. She's been doing it for at least 20 years and used to swim as many as 60 laps daily."
For her 99th birthday, her regular swimming companions feted her with a poolside party, featuring a pink cake topped with ballet shoes.
"You know, I wasn't always so popular, my dear," she told Carey. "I could be ornery, and I often behaved meanly.
"But it seems people are liking me more now, probably because I"m getting feeble and descending into the grave."
There were no survivors and no services.
Contact staff writer Walter F. Naedele at 215-854-5607 or email@example.com.