(Photo Credit: Entertainment One)

Naomi Watts was admittedly "torn" when offered the iconic role of Princess Diana for an upcoming biopic.

A mother of two boys, Alexander, 6, and Samuel, 4, Watts told UK's Sunday Times she was worried about how Diana's children William and Harry would feel about her portrayal.

"I do care deeply about how the princes feel, of course," she told the Times.

Watch: Naomi Watts Shines as Princess Diana in New Trailer

She cared so much that she initially turned down the role twice, only to finally accept the titular role in "Diana," set to be released this fall.

Her concerns almost reached a breaking point when Watts had an awkward run-in with William.

"There was actually quite an eerie moment in London when I did see Prince William in a restaurant," she added. "I got very nervous, because if I caught his eye, I didn't want to interpret a look and think he had a negative feeling about this idea, so I made sure not to look."

See: Princess Diana Through The Years

In the movie, "Lost" star Naveen Andrews plays Diana's love interest Hasnat Khan, the heart surgeon she met toward the end of her life before she died in a car accident in 1997.

Khan, 54, isn't as concerned about the boys as Watts, but recently slammed the movie, saying the plot got it wrong.

Related: Princess Diana Film 'Completely Wrong,' Ex-Lover Says

"It is based on gossip and Diana's friends' talking about a relationship that they didn't know much about, and some of my relatives who didn't know much about it, either," he told the Daily Mail on Sunday. "It is all based on hypotheses and gossip."