Cressida Bonas' brother says she's finding it "challenging" dating Britain's Prince Harry.
Jacobi Anstruther-Gough-Calthorpe isn't sure whether his 24-year-old half-sister could cope with marrying into the royal family because she's such a "sensitive" soul and is distressed by the constant media attention.
He told London's Evening Standard newspaper: "Cressida is not a tough cookie at all. She's a very sensitive, sweet girl. It's challenging, you can't deny it. It's not something that is easy for anyone dating a royal or marrying into the family.
"On some level it is different to any other type of fame. It's an invasion of privacy, which is hard. There are people who court that but when you spend your life hiding from it, I think that becomes very exhausting. I think it's a very difficult thing."
Cressida has been seeing the 29-year-old prince for over 18 months and their relationship is becoming increasingly serious, with Harry taking her out on an increasing number of public dates and the blonde beauty reportedly giving up her dancing career for a more royal-friendly PA job in London's West End.
Her family - which also includes the socialite's half-sisters Isabella, Georgiana and Pandora - are starting to feel nervous about the potential of becoming Harry's in-laws, especially after the spotlight that was thrust upon the Middletons when Catherine wed Prince William in April 2011
Jacobi added: "It does worry me. But sometimes you've just got to go along with life."
Tagged in Prince Harry Duchess Catherine Cressida Bonas