Kate Middleton looked serene and relaxed in an official new portrait marking her participation in an initiative for the Royal Foundation Centre for Early Childhood.

In the outdoor image — taken by photographer Josh Shinner on Thursday — the Princess of Wales, 44, wore a colorful patterned sweater with a floral collar and cuffs, layering the look with an olive green coat.

She wore simple dangling earrings and styled her long, brunette hair in soft curls. Her massive sapphire ring from Prince William — which previously belonged to the late Princess Diana — was visible in the portrait.

In a video announcing the upcoming project — which, according to the caption, examines “how nature can support the healthy development of babies and young children” — Middleton noted “just how important nature is for our physical and psychological wellbeing.”

The mother of three added that “Nature is such an extraordinary environment for us all and in this tech-driven, digital age, spending time outdoors has never been more important.”

She concluded, “My hope is through this practical nature-based research, we can build supportive environments that make nature more accessible, benefitting babies, young children, and their families across the UK.”

The program is set to launch next year.

The portrait’s release comes a day after Prince Harry, 42, and Meghan Markle, 45, made their return to UK public life with their first official joint appearance in the country since moving back in August.

The couple was snapped stepping out in Nottingham on Thursday morning, with the As Ever founder declaring to a bystander that “it’s great to be back.”

Markle received a balloon and a yellow rose bouquet while chatting with bystanders during the outing, which took place in the same city the Duke and Duchess of Sussex announced their engagement back in 2017.

Authorities were reportedly forced to intervene in the sighting after crowds mobbed the couple’s Range Rover and blocked them as they attempted to make an exit.

Prince William, 44, and his younger brother have been embroiled in a longtime feud — though sources told Page Six in August that Prince Harry and Markle made the unexpected move in part to enable their children, Prince Archie, 7, and Princess Lilibet, 5, to build relationships with Harry’s family.

The Duke and Duchess of Sussex famously left the UK back in 2020 for a life in Southern California.