Prince Harry and Meghan Markle's daughter Lilibet turns one next week but the royal diaries are believed to be "full" with events concerning the Platinum Jubilee.
It is said there "isn't much wriggle room" for the Duke and Duchess of Sussex to fit in a royal celebration for their daughter, who will turn one on Saturday June 4.
The Queen, 96, is set to spend Saturday afternoon enjoying the Derby in Epsom, Surrey, while other royals fly across the UK to Jubilee events this week.
Harry, 36, and Meghan, 40, have vowed to attend the Jubilee and want to bring son Archie, three, and baby Lilibet to stay on the Windsor estate.
But a royal source told The Sun: "Harry and Meghan will want to celebrate Lilibet’s birthday somehow with their family.
"But diaries are full on Saturday.
“There isn’t much wriggle room to fit in a birthday party for a one-year-old.
"These events have been planned far in advance and the Sussexes have not exactly made their plans clear or public."
Senior royals are due at a two-and-a-half-hour music party at Buckingham Palace on Saturday night.
Platinum Jubilee celebrates the monarch's 70 years on the throne.
Events will be taking place across the country, including a four day bank holiday weekend from Thursday June 2 to Sunday June 5.
