Was Kate Middleton's dress at Pippa's wedding boring or beautiful? That's what fans are debating in the hours after Pippa's stunning ceremony at St. Mark's Church.

Kate Middleton wore an Alexander McQueen dress to the ceremony, just as she did to her own wedding. This time she opted for a vintage-style frock by Sarah Burton. The dusty-pink hue was divine. And the fascinator perfectly framed her face. But the gathered fabric totally concealed Kate's gorgeous figure.

CLICK HERE TO SEE MORE PHOTOS FROM PIPPA'S WEDDING ...

It makes sense that Kate Middleton chose a modest dress for her sister's wedding. She didn't want to overshadow Pippa on her big day. That's the same reason she wasn't in the wedding party

But style critics say Kate should have chosen a more form-fitting silhouette that would flatter her slim physique. Though Sarah Burton is a huge talent, this particular dress seemed to miss the mark. The loose bodice and baggy sleeves did nothing for Kate's statuesque frame.

Kate Middleton Pippa Dress Kate Middleton helped Pippa with her dress before the bride walked down the aisle (Photo: WireImage).

Nevertheless, it's clear that fashion wasn't Kate's priority today: her sister was. The Duchess was photographed adjusting Pippa's train before she walked down the aisle. Pippa similarly carried Kate's train for her wedding to Prince William. "Kate very much appeared to be attendant-in-chief and was laughing and giggling with Pippa," a source told E! News. 

HOW MUCH DID PIPPA'S WEDDING COST? DETAILS ...

Kate also made sure all the children in the wedding party — including Princess Charlotte and Prince George — were on their best behavior. Another picture showed her shushing the kids as they headed into the church.  "When the children were at the archway, Kate stepped in to keep them under control and crouched down to speak to George and Charlotte," an insider added.

Kate Middleton And Charlotte Kate Middleton made sure Charlotte and the other kids were on their best behavior (Photo: Getty Images Entertainment).

In fact, Kate had been worried about how her kids would behave at the wedding.  "She said that they were all really looking forward to her sister’s wedding at the weekend, but she was a bit worried about how her children might behave," said Andrew Bates, who spoke to Kate at a garden party earlier this week. "She said she was hopeful that they would be good, but you never know at that age."

FIND OUT HOW JAMES MATTHEWS EARNED HIS FORTUNE ...

Kate deserves credit for staying in the background all day – both literally and figuratively. But some are wondering if she went overboard trying not to upstage her sister. Could she have found a middle ground?

Do you think Kate Middleton's dress was too matronly? Let us know your take in the comments section below!