Kate Middleton and Prince William are "more open" and "talk about their relationship together" amid her cancer journey, a source tells PEOPLE.

When Kate Middleton celebrated her 43rd birthday on January 9, her husband Prince William wrote a tender message and shared it on the couple’s public Instagram account. According to royal expert Ingrid Seward of Majesty magazine, the display of affection was a sign that the couple has grown closer following Kate's cancer diagnosis in early 2024.

William, Kate and their three children call Apartment 1A at Kensington Palace their London home - and there is a major change coming to the area that has personal ties to the family