Since the Princess of Wales is away from her royal duties due to her cancer battle, the King has been looking for a replacement to fulfill those functions, and everything seems to indicate that it is the Duchess of Gloucester, Birgitte Eva Henriksen, who will assume Kate Middleton‘s engagements.
Since her marriage to Prince Richard of Gloucester in 1972, Henriksen has shown how important the monarchy is to her, as she quickly became an active member of the royal family, which allowed her to represent the royal family on numerous international tours.
The Duchess of Gloucester is the patron of important academic institutions such as the Royal Academy of Music as well as the Royal Lawn Tennis Association; this last one is what makes her the most likely candidate to replace Kate Middleton at key events such as Wimbledon.
What most characterizes the wife of Prince Richard in her charitable work and service to the Crown is discretion and commitment, to the point that the monarchy has highlighted her efforts with multiple orders and medals. The Duchess undoubtedly has the experience and support of the King to be officially the replacement for the Princess of Wales.