15-year-old Elianne Andam died at a bus stop last September.
The painting, located near the site where she was killed, depicts her smiling.
Community members prayed, sang and paid tribute to Elianne at an outdoor service earlier.
A teenage boy, who cannot be named because of his age, pleaded guilty to her manslaughter but denied murder in March.
The plea was not accepted by prosecutors and a trial is set to take place next month.
The boy also denied possessing a blade in a public place.
