The one message that her mother, Tricia Norman, cannot forget urged Rebecca Ann to kill herself.
"'You haven't killed yourself yet,'" Norman recalled the message saying. "'Go jump off of a building.'"
And that is exactly what Rebecca did, her mother said.
Her mother said she seemed sadder.
"She went to counseling for about three or four months after that," Tricia Norman said. "Her last appointment, the counselor asked how she felt and she said she thought she was doing a lot better."
Rebecca changed schools, and her mother took her cell phone away and monitored Rebecca's online accounts.
But police say the bullies began to target Rebecca on social media that her mother didn't know about.
Authorities are looking at whether they can file cyber-stalking charges against the middle-school students.
"Where do they get this hatred from?" Tricia Norman asked. "Who's teaching the hatred to these kids, that they're just going to be that mean to somebody?"
Norman said she wanted the girls responsible to pay for her daughter's death.
"Because they took my baby away, they took her confidence away," she said, crying. "They took her self-worth away. And now she's gone from me."
Rebecca kept a journal, in which she wrote: "How many lives have to be lost until people realize words do matter?"