The former 'Dawson's Creek' star has reportedly invited Angelina and her eldest girls Zahara, 4, and Shiloh, 2, for tea and cupcakes with her two-year-old Suri at their New York home.
A source said: "Katie loves entertaining and spoke to Angelina about having an at-home tea party with cupcakes for the girls."
Another source adds: "It's something she has wanted to do for ages. Because of security reasons, Katie can't have just any child over to her home. "But with celebrity tots like Shiloh and Zahara, there's no problem."
Katie, 30, and Angelina, 33, have both relocated their families to New York while they work on upcoming films.
They started planning the playdate in Los Angeles in January when Angelina and her partner Brad Pitt met Katie and her husband Tom Cruise at a private Golden Globes after-party at the Sunset Tower Hotel.
Tom, 46, and Brad, 45, first met when they co-starred in 1994 film 'Interview with the Vampire', but failed to stay in touch over the years.
A source said: "Since the film, their careers and social circles have become so different, they rarely see each other. But at the party both talked at length about their children and they agreed to get their little girls together."
Katie and Tom are said to be keen to introduce Suri to children her own age because her adopted siblings - Connor, 14, and Isabella, 16 - are much older.
An insider said: "Suri's a very shy young lady. Even when Tom or Katie have taken her to a park or beach and tried to introduce her to other kids for a little playtime, it hasn't worked. She's very clingy."