The Princess of Wales' sister celebrates 41st birthday

Pippa Middleton recently celebrated another trip around the sun! The Princess of Wales' sister turned 41 on Sept. 6.

She was born to Carole and Michael Middleton in 1983. Pippa is the Middletons' second child. Carole and Michael are also parents to son James Middleton.

Pippa married her husband James Matthews in 2017 at St. Mark's Church. They have since welcomed three children: son Arthur and daughters Grace and Rose.

The mom of three supported her older sister at Wimbledon earlier this year. Pippa attended the tennis tournament with the Princess of Wales and Princess Charlotte in July. The outing marked the Princess of Wales' second official public appearance of the year. 

© Karwai Tang

Catherine began a course of preventative chemotherapy in late February. After announcing in March that she was undergoing treatment, the royal's brother wrote on his Instagram: "Over the years, we have climbed many mountains together. As a family, we will climb this one with you too ⛰️❤️." 

Ahead of her first public appearance of the year in June, Her Royal Highness shared an update on her treatment. At the time, the Princess revealed, "I am making good progress, but as anyone going through chemotherapy will know, there are good days and bad days. On those bad days you feel weak, tired and you have to give in to your body resting. But on the good days, when you feel stronger, you want to make the most of feeling well."

"My treatment is ongoing and will be for a few more months. On the days I feel well enough, it is a joy to engage with school life, spend personal time on the things that give me energy and positivity, as well as starting to do a little work from home," she continued, noting back then that she was "not out of the woods yet."

The Princess concluded her written message saying: "I am learning how to be patient, especially with uncertainty. Taking each day as it comes, listening to my body, and allowing myself to take this much needed time to heal. Thank you so much for your continued understanding, and to all of you who have so bravely shared your stories with me."