Sarah Ferguson recently announced her new partnership amid ongoing rumors that she and Prince Andrew are back together.

On National Siblings Day, the Duchess of York announced that she has offered her support for the Children’s Brain Tumor Foundation on their latest campaign. To show her commitment, Ferguson uploaded a video of herself wearing a white t-shirt which featured the word sister on it.

The t-shirt also featured a dictionary definition of a sister, which includes “superhero,” “always caring,” and “someone to share secrets and laugh endlessly with.” In her caption, Ferguson shared more details about the foundation’s latest campaign.

“The #SiblingSupportProgram will be the first and only national support program for siblings impacted by a childhood brain and spinal cord tumor diagnosis. Celebrate your siblings with this limited edition brother and sister tees and hoodies and 100% of the net proceeds will benefit @childrensbraintumorfoundation,” she wrote.

In another post, Ferguson also uploaded a snap of herself and her sister, Jane, who is currently residing in Australia. In her caption, the mom of two said that her sister is very important to her and she loves her more than ever even though they are apart.

Ferguson’s recent Instagram posts came in heels of rumors suggesting that she has already gotten back together with Prince Andrew. The couple divorced in 1996 after a 10-year marriage. But this month, a royal expert said claimed that the Duke and Duchess of York are friends with benefits.

Royal commentator Dan Wootton noted the fact that Ferguson and Prince Andrew are both single and they also never married other people after their divorce. The parents of Princess Beatrice and Princess Eugenie have also maintained an amicable relationship with each other.

“I have learned they are at the moment in a relationship that is described as friends with benefits. While they have lived in this house for some time, the lodge at Windsor, they are now back committed to each other,” he told Express.

Sarah Ferguson Sarah Ferguson arrives to take her seat inside St George's Chapel ahead of the wedding of her daughter Britain's Princess Eugenie of York to Jack Brooksbank at Windsor Castle, in Windsor, on Oct. 12, 2018. Photo: Getty Images/Yui Mok