They're still adjusting to parenthood after welcoming their first son, Archie Harrison Mountbatten-Windsor into the world on May 6 this year.
However, it seems Meghan Markle and Prince Harry are already planning baby number two.
Speaking to Entertainment Tonight, royal author Katie Nicoll revealed that the couple hope to give Archie a brother or sister very soon.
Sources close to the couple told me that they really would love to have a big family," Ms Nicolls said.
"They absolutely want siblings for Archie, so possibly we will have a pregnancy announcement for Meghan and Harry sometime next year."
She continued: "But for the moment, the focus is obviously Archie."
And as it turns out, the Sussex's aren't the only ones set to make an exciting announcement any day now.
Royal experts believe the hype surrounding baby Archie may have "tugged at the heartstrings" of William and Kate, now little Louis is approaching his toddler phase, Express.co.uk reports.
In recent months, inside reports from Kensington Palace have consistently claimed the 37-year-old Duchess has her heart set on one final addition to her young royal family.
"Catherine would like a fourth child," a source told Daily Mail.
"She loves children and is prepared to put herself through another pregnancy even though they have been complicated in the past."
Speaking to New Idea, another source revealed: "Kate has seen the bond between George and Charlotte and thinks it would be lovely if Louis had a sister closer to his age."
"Kate is doing things her way, but William has always supported her and will do anything to make her happy; that is a promise he made before they married."