A memorial Mass was held for her at Sacred Heart Schools on Feb. 1. A Mass of Christian Burial took place Feb. 2 at the Oakwood Retirement Community chapel.
Sister Costello had a particular affinity for educating boys and she developed strong bonds with the former altar boys she once supervised at St. Joseph elementary school, part of Sacred Heart Schools, according to a 2007 Almanac feature story on her.
They called her the "Flying Nun" or "Hurricane Helen," and she held social gatherings for them in her cottage, which the boys dubbed "The Castle," because it was "such a dump," Sister Costello said. The boys took on renewal of the cottage and refurbished what was once an old cow-tenders cottage.
The Castle was used as housing for parents of terminally ill children at Stanford Hospital or others who needed a place to stay overnight. Sister Costello hosted teen parties, even entertaining the Stanford football team on three occasions. She counted football players Dan Pastorini, Don Bunce and Jim Plunkett among her flock.
In her cottage, Sister Costello kept a bulletin board with more than 200 pictures of children and teenagers, many bedridden or in wheelchairs. All these were children she had befriended, often sitting at the bedside of a dying child. When a child passed away, she often would arrange the burial and drive the body to the mortuary herself.
There were also clippings of the famous 1976 Chowchilla kidnapping on the bulletin board, according to the Almanac article, in which Richard and James Schoenfeld of Woodside and Fred Woods of Atherton hijacked a bus full of children and left it entombed in a quarry for ransom.
Three years later, after an inspiring homily at Mass, Sister Costello visited the kidnappers in prison, and she revisited them several times.
Sister Helen Costello grew up in Los Altos and graduated from Sacred Heart Academy in Menlo Park (now Atherton). She wanted to enter the Society of the Sacred Heart, but her family disapproved. She worked for several years in San Francisco department stores, but followed her call to religious life and entered the Society in 1939. She professed her final vows in Rome on Feb. 9, 1949.
Her first assignment was her own alma mater in Menlo Park. In the 1950s, she spent five years at Forest Ridge Academy of the Sacred Heart in Seattle, and summers at San Francisco College for Women (now the Lone Mountain campus of the University of San Francisco), where she earned her bachelor's and master's degrees. In 1956, she returned to St. Joseph's elementary school, where she remained as a teacher for 16 years.
Sister Costello was born in San Francisco on Oct. 14, 1918. She is survived by her sister Kathleen Costello of Cupertino, brother-in-law Albert Horn of San Mateo, sister-in-law Margaret Ann Costello of San Francisco, and nieces and nephews.
Memorial contributions may be made to the Society of the Sacred Heart, 4120 Forest Park Avenue, St. Louis, MO 63108.