Kate Middleton, Prince Louis
Kate Middleton is still on maternity leave and taking care of Prince Louis. Pictured: Middleton, Prince Louis departs the Lindo Wing with her new born son Prince Louis of Cambridge at St Mary's Hospital on Apr. 23, 2018 in London, England. Getty Images/Chris Jackson

Kate Middleton missed the Buckingham Palace Garden Party on Tuesday for a valid reason.

Duncan Larcombe, a royal biographer, told Express that Middleton is still on her maternity leave at the moment. The Duchess of Cambridge gave birth to Prince Louis last month.

Middleton was seen in public on Saturday for the wedding of Prince Harry and Markle. She attended the huge event as a member of the royal family. Her two children, Prince George and Princess Charlotte, were also part of the entourage as a page boy and a bridesmaid.

But technically, Middleton is still on her maternity leave, and this will last for about six months.

“It is a tradition for new royal moms to take a six-month break from official engagements. The wedding doesn’t count because it was a ‘family affair’ but other than that, she will pick and choose her engagements,” Larcombe said.

In June, royal fans may also see Middleton in public again for the Trooping of the Color. This will also serve as Queen Elizabeth II’s official birthday celebration.

Meanwhile, Prince William was also unable to attend the garden party on Tuesday. He was in Manchester to commemorate the first anniversary of the bombing that took place during Ariana Grande’s concert last year.

On the royal family’s website, it was written, “Today, the Duke of Cambridge attended the Manchester Arena National Service of Commemoration at Manchester Cathedral, marking one year since the attack on Manchester Arena. The multi-faith service remembered those who lost their lives in the tragedy and was attended by the bereaved and survivors.”

Prince Charles, Camilla Parker Bowles, Prince Harry, and Meghan Markle were present at the garden party. The 33-year-old Duke of Sussex even gave his dad a touching tribute to celebrate his upcoming 70th birthday in November.

In his speech, Prince Harry also credited Prince Charles for inspiring him and Prince William to focus on the causes that are closest to their hearts.

“His enthusiasm and energy are truly infectious; it has certainly inspired William and I to get involved in issues we care passionately about and to do whatever we can to make a difference,” he said.