Guy was known for her "bright smile, contagious joy, and tenacious spirit."
"She's just a beautiful person. She's going to be missed by a lot of people. I didn't even know how many people she met," mother Angela Guy said. "They just saw her in the hallway smiling. She just touched them somehow."
"She's a real sweetheart; she's a real sweet girl for sure," said Jacquis Wallace, a classmate from Athens Drive High School. "You just can't believe that happening to somebody like her."
Guy was an honor roll student in high school. She then followed in the footsteps of several family members and attended NC Central University.
SEE ALSO | Husband of Cary triple shooting victim describes trauma of tragic discovery
Husband of triple shooting victim describes trauma of tragic discovery
Guy received scholarship money for college, along with 19-year-old Xavier Holton.
Angela Guy said the couple met in school and started a relationship.
Last Monday, Guy, Holton and his mother 54-year-old Erica Holton were all found shot to death inside a Cary home.
"She was trying to help him and she really loved him," Angela Guy said. "I cared about him like he was my own son. I just wanted him to get better, and so did she."
Cary Police Department said investigators are aware Holton was battling mental health issues. A search warrant shows he was found dead in a bathroom with a gun nearby.
Police are still investigating the circumstances and waiting for autopsies to be complete.
Angela Guy said she'll never really have closure.
"I told her to back off, but she couldn't," she said. "I just wish people had recognized the certain signs."