Prince William and Prince Harry presented the 'Diana Award' on Thursday to 20 people.
Middleton will wed James Matthews on Saturday in Englefeld, England.
Kate Middleton's younger sister is set to wed multi-millionaire James Matthews on May 20.
The royals were all smiles while hosting a bash at Buckingham Palace on Saturday.
The romance continues!
The 'Suits' star rocked a classy ensemble while watching her royal beau compete in the Audi Polo Challenge charity match.
The 32-year-old royal was all smiles while spending time with Ollie and Amelia Carroll, who both have been diagnosed with the incurable genetic disease.
The British royals turned out to support runners and mental health awareness.
The royal pair attended the 2017 Virgin Money London Marathon in England on Sunday.
The royals are continuing their week-long campaign promoting mental health.
The Duke and Duchess of Cambridge and Prince Harry continue their efforts to remove the stigma surrounding mental health.
The 35-year-old royal is encouraging others to express their feelings.
The royal opened up about his own mental health after advocating others to do so.
He spoke out in the same podcast where he opened up about seeking therapy treatment.
