Video footage was captured by an eyewitness over the weekend when Kate, along with her husband, visited a farm shop near Windsor Castle, Sun reports.
Earlier this year, the Princess of Wales underwent abdominal surgery (the details of which were not disclosed) and withdrew from all public engagements until her full recovery.
It is expected that she will return to her duties after Easter on the Gregorian calendar (which falls on March 31st this year).
The prolonged absence from the public eye has created numerous conspiracy theories, which were further fueled by events surrounding the publication of her official photograph on March 10th. Leading agencies soon recalled the image after discovering signs of digital manipulation.
The following day, Catherine apologized for the misunderstanding, explaining it was due to her own experiments as a novice photographer.
On the new footage, the princess appears healthy and rested, which may dispel speculations about her condition at least partially.