The birthday party is a not-to-be missed annual event at Menlo Rec, where Ms. Crowder taught dancing and exercise for so many years. Daughter Sue Miller has been hosting the party since her mother reached 85.
Party-goers were students of Ms. Crowder, who first designed her exercise class in 1949 and taught it for 50 years.
First called "Mariantics," then "Forever Fit," the class has always emphasized a smoothly flowing set of exercises and stretches that work everything from the face to the feet.
When she retired, daughter Sue took over. Cyndi Jung now teaches "Forever Fit" on Monday mornings.
Nancy Schumacher of Menlo Park was among those who came to pay tribute. She took exercise classes 40 years ago, at the same time her daughter, Carol, enrolled in Ms. Crowder's dance class for children.
William Grindley of Atherton was a student with Ms. Crowder from 1974 to 1983. That's nothing compared to his wife, Susan, who took lessons from the time she was a little girl.
"We have a relationship that goes back 57 years," he said. "My wife and her five sisters all took classes from Marianne, as well as their mother, Helen. We've become good friends. We have her over to the house whenever we can."
A native of Colorado, Ms. Crowder studied dance and theater arts for years, heading the dance department at Colorado College. After moving to Palo Alto, she started teaching dance on the front lawn of the family home. Today she still lives in Palo Alto, in the same home she and her late husband, Paul, moved into in 1938.
Ms. Crowder's two daughters, Sue Miller, and Anne Gully of Tempe, Arizona, were on hand for the party, along with Anne's husband, Tommy, and two daughters, Emma and Megan. The next day, there was to be a family party with the grandchildren and great-grandchildren.
On Friday, however, when nearly 100 guests crowded in for a hug or a chat with their beloved teacher, it was a time for Marianne's former pupils to feel they were all in the family.