Nearly 75 people attended the vigil held at Orizaba Park near Spaulding Street and Orizaba Avenue where the victim was killed.
Kellye Taylor, 53, was at a playground watching her students play when she was stabbed to death around 1:30 p.m.
Her loved ones left flowers and candles at the spot where she was stabbed.
Investigators said Steven Brown, 50, of Long Beach walked up behind Taylor and stabbed her before fleeing. Brown, the father of Taylor's grandchildren, was caught at the intersection of Anaheim Street and Redondo Avenue, a few blocks away from the park.
According to family members, Taylor had custody of the four grandchildren from her daughter's relationship with Brown.
"There are some reports that there were some custody issues with (Brown's) children but I can't confirm that," said Long Beach Police Department Sgt. Aaron Eaton.
The possible motive for the murder remains unknown.
Officials said a weapon was recovered near the park.
Taylor was a teacher at Huntington Academy, a small elementary school in Long Beach owned by her mother. The private school where Taylor worked will be closed Monday, Tuesday and Wednesday.
Brown was being held in lieu of $1 million bail.