Queen Camilla was reportedly so determined to show up for a royal engagement Thursday that she didn’t let a little thing like catastrophic weather stop her.

On Thursday evening, Camilla made her first public appearance since the announcement that her husband, King Charles III, had been diagnosed with cancer. She attended an evening concert at Salisbury Cathedral in Salisbury, England, and while she was smiling in footage of the solo engagement, things weren’t quite so smooth behind the scenes.

Inclement weather reportedly grounded the helicopter Camilla was set to board at Sandringham, where she had been spending time with Charles, to make the approximately 200-mile trip to Salisbury for the event. Instead of canceling, according to The Telegraph, she decided to travel by car, a journey that took at least six hours.

“The flight was canceled due to the weather so she elected to go by road, which is one hell of a journey—at least six hours in these conditions,” an unnamed source told the newspaper. “She did not want to let down the king, having assured him that she would continue with her schedule of official engagements.”

At the event, when a fellow guest asked after the king’s health, Camilla responded, “He is doing extremely well under the circumstances. He is very touched by all of the letters and messages the public have been sending from everywhere. That’s very cheering.”

With Charles off the schedule for the foreseeable future as he undergoes treatment for the unspecified cancer, as well as daughter-in-law Kate Middleton, whose recovery from abdominal surgery will keep her away from royal duties until Easter, Camilla and other senior royals are carrying the family’s appearance schedule. Prince William returned to work this week with an appearance at an Air Ambulance gala Wednesday, and will maintain a reportedly scaled-back schedule after taking time off to be with wife Middleton and their three children. It’s Camilla, however, whom sources told Vanity Fair is the “quiet power behind the throne.”

Charles, sources tell VF, is “frustrated” that his outpatient cancer treatments, which will take place in London with recoveries in between at Sandringham, are keeping him away from his royal duties as king.