Her sister, Pippa, is organizing the event celebrating the impending birth of Kate's first child with her husband, Prince William, The Sun newspaper reported. The baby is due in July.
"It isn't royal tradition but Kate isn't a traditional royal," a friend told The Sun about the baby shower.
"She is modern and wants a normal life. Prince Harry, Kate and William are the royal family's link to the younger generation. A baby shower wouldn't normally happen if you're in the royal family, but there is now a modern way of thinking.
"It will be a great day for everyone and Kate is doing this with the blessing of the queen."
The party will feature a pacifier-shaped cake from the bakery run by Kate and Pippa's brother, James, the newspaper said.
The date and location of the shower weren't reported.