Ashton and partner Mila Kunis have been careful to keep little Wyatt out of the public glare since her arrival on October 1 last year.
But as this photo shows, if this really is her, their tiny tot is growing up fast!
Ashton uploaded the gorgeous picture of the cute girl pointing to the sky near their home at Lake Hollywood to raise awareness for the Red Sand Project.
The organisation is an art collective aiming to help stamp out modern-day slavery.
It asks people to pour red sand into sidewalk cracks and share photos with the #RedSandProject hashtag.
“39 million people have fallen through the cracks into modern day slavery,” Ashton writes in a his post.
Although Ashton stops short of confirming it’s Wyatt in the shot with the cute floral shirt and vibrant three-quarter length trousers, Twitter fans are adamant it’s really her.
Those closest to the pair also say they take Wyatt with them everywhere they go.
“Ashton and Mila include Wyatt in everything,” said one report.
“They take her on hikes, out to breakfast and to the beach. She loves being outside so that’s a big part of her routine.
“They’ve done a lot of road trips and think she’s very adaptable and easy-going.”
Despite Mila and Ashton’s reluctance in showing off Wyatt, they still manage to see the funny side in the overwhelming interest from fans.
“We immediately went home and reserved all the domain names [after the birth],” Ashton said last year.
“We’ve got the Twitter handle – the Instagram- everything you could possibly get.
“I don’t want a porn site with my daughter’s name!”
Reporting by James Graham