According to The Telegraph, Claire made the speculative remarks at a debate held at Marlborough College, the same institution where Middleton went to school.
"I think Kate Middleton is pregnant - and that would be good for the economy," Claire reportedly said.
Her comments, based merely on assumption, were immediately fired with criticism from Royal observers who said her rant was "unhelpful" and "none of her business," The Telegraph reported.
"Unless she has visited the same gynecologist it strikes me as extremely unlikely she might know," Royal historian Hugo Vickers told The Telegraph. "It's quite clearly none of her business to make remarks of that kind, and presumably it is not very helpful either. She seems to be a bit of a loose cannon, and this is probably more loose cannon fire from Mrs. Perry."
Vickers added that Claire could be "trying to make a bit of a name for herself" by mentioning Middleton being pregnant, something fans and even foe have been wondering since she tied the knot with Prince William last year.
Royal observer Ingrid Seward told The Telegraph that speculation about a new royal is nothing new.
"Historically there has always been speculation about this sort of thing, and of course you cannot stop people saying what they want," Seward said. "I should think the Duke and Duchess of Cambridge are probably pretty used to it but also pretty fed up with it."
Seward added that speculation of pregnancy is itself pointless when it comes to the royal family as until an announcement is made officially by the Palace, there is just no room for rumors.
"It will be the best-kept secret of all time. There is no way they would want people to know before it was appropriate."
Labor MP Chris Bryant described Claire's remarks as "a bit odd," especially since the panel in which Claire spoke was about the Olympics as it pertains to the economy.
"I don't know how it ended up with whether Kate Middleton was pregnant or not," Bryant said.
However, for many it comes as no surprise as basically every other day, a new report surfaces that Middleton is with child.
Most recently, Middleton and Prince William were attending a Thistle Service in Edinburgh, Scotland on Thursday, since the couple was named Earl and Countess of Strathearn. Middleton was seen with what onlookers called a "baby bump" which she attempted to hide with a scarf.
There has not yet been an official announcement from the Palace as to whether or not Middleton is pregnant, but in May, Prince William told Katie Couric of ABC News that he'd "like to have children" with his wife of one year.
"I'm just very keen to have a family and both Catherine and I, you know, are very much looking forward to having a family in the future," Prince William said.
When Couric asked if there was anything he would like to announce, the Prince responded, "You won't get anything out of me. Tight lipped."