Princess Kate's sister Pippa Middleton faced a dilemma seven years ago when she was planning her wedding to James Matthews, a royal expert says.

The ceremony, which took place on this day in 2017, featured Prince George as a pageboy and Princess Charlotte as a bridesmaid.

Naturally, Kate and Prince William were in attendance, but the question of whether to invite Prince Harry's then-new girlfriend Meghan Markle proved problematic.

The couple's relationship had recently become public knowledge, sparking interest from Royal enthusiasts eager to see them together.

According to the book "Finding Freedom" by Omid Scobie and Carolyn Durand, Meghan had intended to attend the wedding and had even purchased a new outfit and hat for the occasion.

However, it was ultimately decided that she should not attend.

The authors suggest that Pippa and her mother Carole were worried that Meghan's presence might "overshadow the main event".

They also mention a headline comparing Pippa and Meghan's bottoms that ran on the morning of the wedding, which reportedly was the final straw, reports the Mirror.

The book reveals: "Harry and Meghan agreed that she couldn't possibly turn up at the church, only fifty metres away from a specially arranged media pen, after such a crass cover story.

"If they worried their arrival might create a media circus despite taking every precaution, now they had no doubt that it would. Meghan's church outfit and Philip Treacy hat would have to be worn another time."

Instead, Harry dropped Meghan off at a friend's Airbnb before heading to the church solo.

While he attended the ceremony, Meghan prepared for the reception, awaiting Harry's return for a private lunch before joining the evening festivities at the Middleton residence.

However, the night didn't unfold as Meghan envisioned, with the couple seated apart due to Pippa's seating arrangements, as Scobie and Durand note: "Sitting together in the custom glass marquee that has been erected on the eighteen-acre property should have been a fun night for the couple, but, per Pippa's request, no couples sat together."

Despite this, Pippa and her family were present at Meghan and Harry's Windsor wedding.

Pippa and James are now doting parents to three young children: Arthur, aged five, Grace, who is three, and Rose, approaching her second birthday next month.