Kate Middleton was concerned about how the public would perceive her return to the spotlight when she appeared at Trooping the Colour after a months-long absence, according to a source.

The Palace announced that the Princess of Wales had abdominal surgery in January. Two months later, she announced that she had been diagnosed with cancer. Since March, she had not been seen publicly until her first public outing at the King's annual birthday celebration. According to a source, the future queen was concerned about the public's perception of her comeback.

"Kate was nervous making her reappearance," a source told Life & Style. "She worried she would look tired or too thin at the parade, but she looked amazing. The supportive response Kate got boosted her confidence, and it was apparent."

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Kate Middleton
Britain's Catherine, Princess of Wales, (R) arrives with Britain's Prince William, Prince of Wales, (L) and Britain's Prince George of Wales (C) to Buckingham Palace before the King's Birthday Parade "Trooping the Colour" in London on June 15, 2024.
(Photo : HENRY NICHOLLS/AFP via Getty Images)

The royal mom of three wanted to show the world that she had not given up. The Duchess of Cambridge returned with her signature grace and style, and her husband and the rest of the royal family were reportedly very proud of her.

"Prince William was very proud of her," the insider said before adding, "and so were the rest of the royal family."

Middleton was seen on the balcony next to King Charles, who also announced her cancer diagnosis earlier this year. She was surrounded by her husband and their three kids -- Prince George, 10, Princess Charlotte, 9, and Prince Louis, 6 -- while they were on the balcony to watch the flypast.

Following the event, Middleton was reportedly "exhausted." Her first public outing "took a lot out of her." The royal mom, who is undergoing preventive chemotherapy, has "bad days," but she wants to be honest about her health battle.

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Kate Middleton Catherine, Princess of Wales
Britain's Catherine, Princess of Wales, smiles inside the Glass State Coach on her way to Horse Guards Parade for the King's Birthday Parade "Trooping the Colour" in London on June 15, 2024.
(Photo : Henry Nicholls/AFP via Getty Images)

Middleton shared an update about her health before her Trooping the Colour appearance. In her statement, she said she was making progress but "not out of the woods yet."

"I am making good progress, but as anyone going through chemotherapy will know, there are good days and bad days. On those bad days you feel weak, tired and you have to give in to your body resting. But on the good days, when you feel stronger, you want to make the most of feeling well," Middleton wrote.

Middleton's first public outing sparked debate. Some speculated that the woman with the royal family was a double. However, many argued it was definitely her while pointing out it was absurd to use a double in public. One sarcastically asked, "Did they teach their children to pretend it's their mother?"

Judi James, a leading communication and body language expert who regularly appears on BBC News, Sky News, GB News and CNN, said Middleton's return to the public spotlight was a "masterclass." The future queen was reportedly "calm with not one drop of self-pity or drama."

Kate Middleton and Roya Family
(From L) Britain's Prince George of Wales, Britain's Prince Louis of Wales, Britain's Prince William, Prince of Wales, Britain's Princess Charlotte of Wales, Britain's Catherine, Princess of Wales, Britain's King Charles III and Britain's Queen Camilla stand on the balcony of Buckingham Palace after attending the King's Birthday Parade, "Trooping the Colour", in London, on June 15, 2024.
(Photo : JUSTIN TALLIS/AFP via Getty Images)