"I'd like to tell him he's welcome to stay and play, she loves the attention!"
She shared the security footage alongside the post, which has been viewed over 1.3 million times.
Within 24 hours, the boy's mother, Ginger Clement Breaux, confirmed the boy in the video was her son, Josh.
"Thanks for the add Hollie! Josh talks about your dog all the time! Every time we pass he looks to see if she was sitting where he could see her. Just didn't know he was doing things like this," she wrote.
"Last night when I first saw it, I was torn as a mumma being happy and upset because he knows he shouldn't be on someone's property, but I wake up this morning more happy that he just absolutely adores dogs so much."
Mallet was thrilled to learn her dog's admirer had been identified and hoped he would continue to visit Duchess.
"So glad to see that innocence and love was caught on camera instead of what they are normally used for. Can't believe all the views this post has received, so glad to have captured this sweetness!"
When Josh was shown the footage, his mother says he "turned shades of red". But he gave her a big smile and told her: "You know I love dogs Mumma."
It turned out Josh also had some documentation of his visits with Duchess too - in the form of cute selfies which his mum shared to Facebook.
When viewers asked why Josh didn't have a dog himself Breaux explained what had happened to their last pet:
"We had our dog Bella since Josh was 2, but she passed away last year. Things have been busy and Josh is active with after school activities so we have not jumped back into taking on the responsibility of starting all over again with a new pup quite yet. It will happen though!"
- nzherald.co.nz