PHILADELPHIA — A 10-year-old girl who had two adult-lung transplants after her parents sued to change national rules regarding organ donations underwent surgery Tuesday to repair her diaphragm.

The operation performed at Children’s Hospital of Philadelphia is expected to allow Sarah Murnaghan to breathe on her own. Sarah has needed a breathing tube since the successful June 15 transplant because she suffered a partial paralysis of her diaphragm during that procedure.

Her mother, Janet Murnaghan, wrote on her Facebook page that doctors said the operation went well.

“Sarah is still mostly sedated, waking periodically in pain, so aggressive pain management is under way,” she said Tuesday evening.

Murnaghan also said her daughter has one chest tube back in place, and doctors expect to know by next week “whether her other muscles are strong enough to do the job of breathing after extubation or if she needs a temporary tracheostomy while we recondition her muscles.”

Sarah has been hospitalized for months with end-stage cystic fibrosis while awaiting two new lungs.