it is a big day for the wales family. louie turns 6 today. and mom kate, princess of wales, is back behind the camera. take a look. this morning prince william and princess kate's third, youngest and most rambunctious child turns 6 years old. and just like previous years, a new candid photo marking the day, snapped by mother kate, released by kensington palace. >> for these annual photographs kate and william released are very beloved by the british public. you know, we like to look at those children growing up. they clearly are very photogenic. >> reporter: louis's birthday comes more than a month after the princess of wales released that photo, meant to reassure the public during a long absence, but causing uproar after it was found photo shopped in several places. we haven't seen the 42-year-old princess since her announcement last month that she's undergoing preventive cancer treatment. >> it has taken us time to explain everything to george, charlotte and louie in a way that's appropriate to them. >> reporter: now the kids are back at sc