HOUSTON (KTRK) -- Juliet Porras says her daughter, Elena, is an amazingly happy child, considering how she came into the world."She was was born with stage three cancer. She started chemotherapy when she was 12 hours old," said Juliet.The disease left her wheelchair-bound and accustomed to challenges, but Juliet believes the most recent challenge the 9-year old is experiencing at Walnut Bend Elementary is unacceptable."The elevator sometimes breaks down, sometimes working, sometimes it's not," said Elena.Elena's third grade class is on the second floor and they've had problems since the first day of school."Monday we got to school it made a little noise, by Monday after school they said it was broken," said Juliet."We felt shaking, it felt like we were going down to the ground, like the elevator would be stuck," said Elena.Houston ISD says it has been trying to repair the elevator, but so far, no success. Juliet says she expressed her concerns to the school at the end of last school year."I would have put a classroom on the first floor, moved her class downstairs," said Juliet.Houston ISD says that's not an accommodation it can make, and says the solution is a reliable elevator for the building. It released this statement:"Maintenance and repair crews have been working hard the past two weeks to address issues with the elevator at Walnut Bend Elementary School. This weekend, the elevator will undergo a major overhaul that should have it fully operational when students return on Tuesday."Juliet remains skeptical."What happens if it doesn't work again? When is enough, enough?" she asked.