• Pippa Middleton, the sister of Princess Kate, is expecting her first child with husband James Matthews
  • Middleton, 34, confirmed the pregnancy in a fitness column for Waitrose Weekend, a magazine for a U.K. supermarket chain

Pippa Middleton, Duchess Kate Middleton’s younger sister, is expecting her first child with her husband, James Matthews.

Middleton, 34, announced the “happy news” using her fitness column where she writes for Waitrose Weekend, a magazine from the U.K. supermarket chain.

“This being my first pregnancy, I had so many questions I felt were still unanswered,” she wrote.

“I wanted to know things like, would I strain if I served in tennis, are strokes of swimming safe, can I still do a normal yoga class if I avoided certain positions? Could I still work my abs?”

In the article, Middleton offers tips for other expectant moms, and suggests lunges, squats and reverse flyes as ideal exercises to stay healthy safely.

A pregnant #pippamiddleton shot for Waitrose . #locationphotography #fitness #pregnancy @waitrose

A post shared by Mark Harrison (@mark_harrison_photography) on

In the same article, she also wrote that keeping the ‘happy news’ a secret has been hard. She also said she’s past the first semester and didn’t experience the same morning sickness her older sister, Kate Middleton, dealt with.

“When I learned the happy news that I was pregnant, I realized I needed to adjust my four to five-day-a-week [fitness] routine,” she wrote; noting that she kept her pregnancy a secret from her gym instructor until the “riskier months” were over.

This won’t be the last we hear of Middleton’s pregnancy fitness regime, as she has promised to share her experiences every month in her column.