The blaze was reported just after 3pm Saturday in the 2000 block of Turner at Aldine Westfield.
When firefighters arrived, they saw smoke and flames coming from the back of the home.
Initially, family members feared someone may be trapped inside, but firefighters searched and confirmed that everyone got out safely.
"She ran to the store, came back, and the house was on fire," the resident's sister, Dalila Quintanilla, said.
The mother's 12- and 13- year-old daughters were OK, but the fire moved through the bathroom and into the kitchen.
Smoke spread into the room where the Christmas presents were ready for Sunday morning.
"All their Christmas presents, just everything," Quintanilla said. "My sister is a single mom and everything she has ever worked for, you know?"
The duplex sustained around $40,000 in smoke and fire damage, officials said. They were able to knock out the fire in about 15 minutes before the structure was completely destroyed.
While the family is dealing with tremendous loss, they are still grateful for what was spared.
"Everybody is . That's what matters," Quintanilla said. "The presents, money comes and goes. That's replaceable. Their lives are not."
Investigators believe the blaze may have started with the bathroom heater. Officials are reminding you to keep track of all the potential fire hazards in your homes, including Christmas trees, lighting, furnaces, candles and space heaters.
