The fire happened in the 6400 block of Portsmouth Drive. Firefighters arrived at the single-story home after 2 a.m. to heavy smoke with six people trapped inside.
A firefighter said one person was also taken to the hospital. Their condition is unknown.
Police and fire departments are investigating.
WATCH: Family member reacts to fatal Fayetteville house fire
"I'm heartbroken. Trying to stay strong for the rest of the family. Long as I keep distracting myself with other thoughts. I'm okay," said Sheri Jones, the victim's cousin. "All we know is the house caught fire and they couldn't get out fast enough."
Jones identified the victims as 30-year-old Amelia Jones and her two sons, fourth-grader Jayden Jones and first-grader Dante Davis.
"I just talked to her before this happened right before we went to sleep. I talked to her on the phone," said Shakeia Jones-Garfalo who is first cousins with the victim. "I just love her so much. I just love her so much."
Family members said, Jones's husband was able to escape the fire.
"My heart goes out to you. You loved her and them babies. You've loved her the way a man should love a woman and I thank you for that," said Jones-Garfalo.
The two boys attended Brentwood Elementary where school officials released a statement Thursday afternoon.
"We are extremely saddened by this news and extend our heartfelt sympathy to their family," school officials said.