She since announced she was in remission in January this year.
In a new interview with Brazilian television host Luciano Huck during his trip to Brazil last week, Prince William spoke after what has been a ‘very tough’ few years for the royal family.
Not only has Middleton been through a cancer diagnosis, but so has King Charles III.
King Charles is still undergoing treatment more than a year after his diagnosis.
The interview took place during William’s five-day visit to Brazil, where he presented the Earthshot Prize.
The heir to the throne also took part in the COP30 climate summit, where he delivered a keynote speech urging world leaders to act decisively to safeguard the planet’s future.
‘We decided to tell our children everything’
During the conversation with Luciano Huck, Prince William spoke about how he and the Princess of Wales broke the news to their kids – Prince George, 12, Princess Charlotte, 10, and Prince Louis, 7 – of their mom’s diagnosis.
He admitted: “Hiding stuff from them doesn’t work.”
Acknowledging every family has its own ‘challenges,’ the Prince said: “Every family goes through difficult times and faces challenges together. How you deal with those moments makes all the difference.
“We decided to tell our children everything, both the good news and the bad. We explain to them why certain things happen and why they might feel upset.”
He added: “Many questions might come up without answers – I think all parents go through that. There’s no rulebook for being a parent, and we chose to talk about everything.”
Prince William and Princess Kate’s bold ban
Elsewhere in the interview, he explained how he and Kate are apprehensive about their children using mobile phones.
He continued: “It is really hard. Our children don’t have phones.
“When George moves onto secondary school, maybe he’ll have one with limited access.
“We talk to him and explain why we don’t think it’s right.
“With full access, children end up seeing things on the internet that they shouldn’t. But with restricted access, I think it’s good for messaging.”