The Duchess of Sussex and Duchess of Cambridge have often been pitted against each other in media stories.
The Duchess of Sussex told Oprah on Sunday, "I just didn’t see a solution."
The two-hour interview will air in Australia just hours after it hits screens in the US.
Fans said Frankel had "hit a new low" in comparing her reality TV career to Meghan's experience in the public eye.
The messages aired hours before CBS broadcasts the Duke and Duchess of Sussex’s highly anticipated tell-all with Oprah Winfrey.
The Duchess of Sussex speaks out in the latest clip from Oprah Winfrey's upcoming interview with Prince Harry and Meghan.
"Were you silent or were you silenced?" Oprah asks the Duchess of Sussex in the beginning of the clip.
The Duke of Edinburgh was admitted to the King Edward VII Hospital in London last week.
The Duke and Duchess of Sussex will sit down with Winfrey for a 90-minute interview called "Oprah with Meghan and Harry."
Reacting to his 'Nature Challenge' video, Kylie Gillies said "there are bigger issues" the Prince of Wales could address during pandemic.