GB News royal correspondent Cameron Walker says Princess Kate "appears to be recovering well" after she was papped while reportedly on the school run.
The Princess was being driven by her mother Carole Middleton near Windsor Castle.
The snaps were taken before 9am, with Kate wearing dark sunglasses for the outing.
UK media outlets have chosen not to publish the photos amid calls for the Princess's privacy to be respected.
Princess Kate is currently recovering from her operation GettySpeaking on GB News, Walker said: "They were unauthorised paparazzi photographs. I'm getting the sense that Kensington Palace is quite upset that the Princess's privacy was invaded in this fashion. The photographs published in the US gossip magazine appear to show her in the passenger seat of a car near Windsor Castle.
"Carole Middleton, her mother, is driving the car. The report is that the photographs were taken just after 9am on the way back from the school run but it does appear to show the Princess of Wales wearing sunglasses and clearly well enough to be in the car.
LATEST ROYAL NEWS:
"So perhaps slightly positive, but it is clearly a very big invasion of her privacy.
"She seemed to look well in the images. So it puts a lot of people's minds at ease.
Cameron Walker said that she "seems to be recovering well"
GB News
"UK media organisations will not be running these photographs.
"But the problem that Kensington Palace has is that it's on social media and everywhere else, so they can't really control that photograph getting out.
"I suppose in terms of all the speculation that we've had over the last few weeks with the hashtag, 'where is Kate Middleton?'
"There has been all these unfounded conspiracy theories springing up online, It does provide that unofficial unauthorised message of reassurance. The Princess appears to be recovering well."
There has been a lots of speculation since she has been absent
PARumours about why Kate has been missing for so long reached new heights last week, with several outlandish theories emerging.
To put an end to the speculation, the Palace said in a statement: "We were really clear from the start we weren’t going to provide a running commentary on the Princess of Wales’s health and only provide significant updates.
"Obviously, we’ve seen the madness of social media and that is not going to change our strategy. There has been much on social media but the Princess has a right to privacy and asks the public to respect that.
"We remind you of the statement in January where it was the Princess of Wales’s wish her medical information would remain private."