Friday would have been Samantha's sixth birthday, and her mother, Erin, has planned a private family celebration with a Peter Pan cake and decorations.
Erin Runnion says the party will be her family's "personal goodbye."
For the Runnions, some anger is mixed in with the tears.
Runnion says she cannot understand the actions of the jury that freed the man now accused in her 5-year-old daughter's kidnapping and slaying.
The suspect, Alejandro Avila, 27, was acquitted last year of molesting two 9-year-old girls, including a former girlfriend's daughter who lived in the same townhouse complex as Samantha.
"I blame every juror who let him go," said Runnion, speaking in an interview on "Larry King Live" on CNN. "Every juror who sat on that trial and believed this man over those little girls, I will never understand."
Samantha was snatched in front of her Orange County home on July 15 by a stranger who used the ruse of searching for a lost puppy. Her nude body was found the next day off a rural highway near Lake Elsinore, some 50 miles away in neighboring Riverside County.
Avila has been charged with kidnapping, murder and sexual assault in Samantha's death. Avila has said he is not guilty.
"I have very little room for anger, very little room, it's all hurt, it's all sadness," Runnion said of her feelings toward Samantha's killer.
Runnion said she hasn't decided whether she would attend Avila's trial.
"The district attorney has my complete faith and our judicial process is going to have to do better this time and I think it will," said Runnion, adding that her one relief is knowing that Samantha isn't in pain anymore.