Kate Middleton's new 'serious' health details worry experts

Kate Middleton, who returned to Adelaide Cottage in Windsor on Monday almost two weeks after her "very serious operation", left royal fans and experts worried with her decision to keep the details private.

Royal commentator Angela Levin expressed her concerns about the Princess of Wales's mystery abdominal surgery, claiming Kate underwent a "very serious operation," adding her stay in hospital was telling.

The royal author, in conversation with GB New, outlined the 'worrying' signs of the royal's health in her own words, saying: "Nowadays people don’t keep you in hospital for very long."

She tried to highlight the future Queen's "serious" heath condition by revealing very crucial details: "They want you to sit up very quickly and out, and particularly for someone like her who has got lots of staff and she can get nurses and doctors at the flick of a finger."

Levin went on explaining: "It must have been a very serious operation and we hear that she won’t be doing any engagements until after Easter. That too its quite worrying. No one would say she should come back earlier of course, but it is a concern."

Praising Kate's steadfastness to the Firm, Levin said she's "not putting a foot wrong" since marrying to Prince William in 2011. She’s given up a lot and she loves the Royal Family. She’s dutiful and she knows what is expected of her. She does it with a smile and enjoyment."

On the other hand, future King Prince William has already cleared his official diary to devote his time to his wife and their three children, Prince George, Princess Charlotte and Prince Louis.