Pippa Middleton-James Matthews wedding: Kate Middleton to be matron of honour?

With just less than a week left for the wedding of Pippa Middleton and James Matthews, the world is anxiously awaiting to know the role Kate Middleton will play at her sister's wedding.

When the Duke and Duchess of Cambridge tied the wedding knot in 2011, Pippa stole the limelight as the maid of honour in a figure-hugging white gown. So, many assumed that Kate could be the bridesmaid at her sister's wedding.

However, the Duchess of Cambridge might not be able to return the favour mainly because traditionally unmarried family members are selected as maids, maid of honour or chief bridesmaid.

Read: Pippa Middleton doesn't want Spencer's girlfriend at the wedding; Is she insecure? 

Although Kate is not eligible for the role, she could be the matron of honour at Pippa's wedding. (Matron of honour is a role that is quite similar to the maid of honour except for the fact that a matron is a married woman.)

Meanwhile, royal author Judy Wade opined that the Duchess could prefer to be in the background for her sister. "Kate would upstage her sister. It's a tricky situation for Pippa. She would want her sister by her side, as who else would she trust to make things go well? But if your sister is a future queen, she is going to upstage the bride and draw attention," she told People magazine.

Meanwhile, the royal kids Prince George and Princess Charlotte will be the pageboy and the flower girl respectively. Prince Harry is also expected to be in attendance on the big day with his girlfriend Meghan Markle.