The former Saved by the Bell actress wore a Justin Bieber T-shirt to the Horrible Bosses premiere last year after Bieber was seen wearing a T-shirt with her image to Canada's MuchMusic Awards.
Asked if she had received any threatening messages from Bieber's notoriously protective fans, Thiessen insisted that she is no competition to his legions of supporters.
"Not that I could see on my Twitter page or Facebook. Believe me, girls, he's way too young for me, so don't worry! I've never met him, but I do understand to a degree what his life is like right now, as a recognisable teen star," she told Parade.
Thiessen went on to say that she feels fortunate to have made it through the world of teen stardom, adding: "The business is ever-changing, and I don't think it's easy for any kid. Thank God I [survived]. Not every story is that way."
The White Collar star welcomed daughter Harper Renn in June 2010 with husband Brady Smith.
Thiessen has commented that Harper is no longer a baby and said that the little girl has reached many milestones in recent months.
Watch the video for Justin Bieber's 'One Time' below: