The mother of a girl who died in the custody of US immigration authorities in Texas last month made multiple requests for an ambulance or hospital-level medical care for her daughter, but a nurse practitioner contracted with US Customs and Border Protection denied the requests, the agency said Thursday.

The 8-year-old girl, Anadith Danay Reyes Alvarez, eventually was taken May 17 to a Harlingen hospital, but she died there that day, eight days after she and her migrant family were taken into custody by CBP in Brownsville.

After the family initially was processed at a CBP facility in Donna, Texas, on May 10, they were taken to the CBP's Harlingen station on May 14 after the girl tested positive for Influenza A and complained of abdominal pain, nasal congestion and cough, the CBP previously said.

From May 14 to May 17, "CBP-contracted medical personnel reported having approximately nine encounters with the girl and her mother, who complained of fever, flu-like symptoms, and pain" at the Harlingen station, CBP said in a new post on Thursday.

The medical personnel treated the girl's fever -- which reached 104.9 degrees on May 16 -- with ice packs, a cold shower and fever reducing medications, and also gave her a flu medication, but "despite the girl's condition (and) her mother's concerns," the child was not transferred to a hospital, CBP said Thursday.

On May 17, the day the girl died, a nurse practitioner at the station saw her four times after the girl complained of a stomachache, nausea and difficulty breathing, Thursday's CBP statement reads. The nurse practitioner reported that the 8-year-old had a normal heart rate and normal blood oxygen saturation levels during each visit, CBP said.

The practitioner also reported "denying three or four requests from the girl's mother for an ambulance to be called or for her to be taken to the hospital," CBP said.

Shortly before 2 p.m. -- and after having seen the nurse practitioner four times by that time -- the mother returned to the health unit holding her daughter, who appeared to be having a seizure, CBP said.

Soon after, the young girl became unresponsive. Medical personnel started CPR, according to the the agency.

The child was taken to the Valley Baptist Medical Center in Harlingen and was declared dead at 2:50 p.m., CBP said.

The CBP's Office of Professional Responsibility, which is investigating the child's death, determined that none of the contracted medical personnel or US Border Patrol employees at the Harlingen station knew Reyes had sickle cell anemia and a history of congenital heart disease, CBP said. The family had reported she had sickle cell anemia and heart disease during a medical assessment at the facility in Donna on May 10, the CBP has said.

While the girl was sick at the Harlingen facility, "contracted medical personnel did not consult with on-call physicians (including an on-call pediatrician) about the girl's condition, symptoms, or treatment," CBP said Thursday. "The contracted medical personnel failed to document numerous medical encounters, emergency antipyretic interventions, and administrations of medicine."