Meghan Markle feels that there is a "very high" standard set by her sister-in-law Kate Middleton.
The Duchess of Sussex can't escape the royal comparisons and feels "discouraged" because of them, reported Us Weekly.
An insider told the outlet that the former 'Suits' actor has this "sense of isolation" being in the U.K.
"It's discouraging that the British public holds her up to that," the source said.
"Meghan has this sense of isolation being in the U.K., subject to cruel British media. Her hands are tied and she isn't allowed to defend herself. It has been very difficult," the source added.
While they both married into the royal family, Meghan and Kate come from very different pre-marriage lifestyles.
The former actor, who tied the knot with Prince Harry in May 2018, was born and raised in California and didn't move across the state until getting engaged to the former military pilot in the fall of 2017.
Meanwhile, Kate grew up in England like her husband Prince William.
"They are different women with different roles from different cultures," the late Princess Diana's former butler Paul Burrell told Us Weekly in April.
"Kate knows that Meghan is no threat to her, and Meghan is mature enough to realize that her role is vastly different to Kate's," Burrell added.
The 'Entertaining With Style' author noted that he doesn't believe there is any "jealousy" between the two ladies but is "sure that they have differences of opinion."
"I have no doubt that Meghan is not a 'yes' person. She speaks her mind and voices her opinions as an American woman of today would and should," Burrell told the outlet.
Although rumours of a rift between the Duchesses have made headlines before Meghan tied the knot to Harry, the two have been "bonding over motherhood" since the Duchess of Sussex gave birth to her and Harry's son, Archie, in May.
"Meghan and Kate will be spending a lot more time together," a palace insider explained to Us Weekly at the time, noting "they've become closer than ever."
Kate shares three children with William -- Prince George (6) Princess Charlotte (4) and Prince Louis, (15 months).
( With inputs from ANI )