She even wants Harry to undergo a deposition but that appears far less likely, say legal sources.
Samantha also says she was defamed in the book Finding Freedom.
Oprah Winfrey could be questioned by lawyers over her bombshell TV interview with Prince Harry and wife Meghan. Photo / CBS
According to the Sun, Meghan's lawyer Michael Kump said Samantha's legal team had "identified a whopping 19 non-party witnesses, including Prince Harry, Meghan's mother, Oprah Winfrey" and others that she wants to depose including the authors of Finding Freedom.
A deposition is a witness's sworn out-of-court testimony. It is used to gather information as part of the discovery process and, in limited circumstances, may be used at trial.
Kump said the deposition should wait until Meghan's request to dismiss the case was decided.
Kump said it is an attempt from Samantha to "rescue her case".
He wrote: "To state the obvious, because Meghan did not write Finding Freedom, she cannot be liable for statements in the book. It really could not be simpler than that".
Meghan's comments to Oprah were protected by the First Amendment, Kump said.