Royal biographer Angela Levin has said that it is "really very concerning" that the Princess of Wales has to spend 14 days in the hospital.
This week, King Charles and the Princess of Wales announced that they are seeking hospital treatment for different conditions.
King Charles was diagnosed with an enlarged prostate on Wednesday and is to undergo a "corrective procedure" next week.
Princess Kate announced she had "successful" planned abdominal surgery on Tuesday, and Kensington Palace announced the operation on Wednesday, just hours before King Charles shared his news.
Kate Middleton is in hospital for 14 days
Getty
In an official statement posted to Kensington Palace's official Instagram page, it was confirmed that she is "unlikely to return to public duties until after Easter."
It was also requested that she be given her privacy at this time whilst she recovers.
Royal expert Angela Levin told GB News this morning: "It's very unusual to stay in hospital for 14 days. If at home you've got all the comfort that you could have with someone coming in and looking after you.
"She could have nurses galore and the children could see their mother. But she is there for 14 days and they seem very firm that she won't be doing anything until around Easter, which is a very long time.
Angela Levin said that it is "really concerning"
GBNews
"I think that's the most scary thing about it. She works so hard and tries so hard that I think it's very concerning that she's there.
"She's not the sort of woman who wants to stay in a hospital."
Levin then added that her devoted husband Prince William may be feeling a bit "lonely" but the "children will cheer him up.
She said: " I think it's a very lonely feeling. And I think that he's doing his best because he's got children.
Kate will not resume public duties till Easter
PA"I think children can cheer you up or something like that, and he's got the responsibility of looking after them.
"For something like that, I think that he goes back to his own mother when he became what she called the man of the house.
"He had to deal with her with her mental illnesses and crying and screaming.
"He'd put tissues under the bathroom door when she locked herself in to help her. I think he took that responsibility on when he was only 15 and didn't quite know what to do.
"But here, he's a mature man and he will know that his priority is to look after his wife, who has been so wonderfully supportive to him."