In the snap, the tiny tot’s mop of blonde hair stands on end as she relaxes in a light pink romper.
“She’s going to be the most genetically blessed little lady! She’s so beautiful already 💕💕💕,” one fan commented.
“Omg THE HAIR 😍,” added a second.
Others, congratulated the pair for making it through the mini milestone unscathed, writing: “Happy four weeks little Elle ❤️❤️,”
Elle is the spitting image of her gorgeous mum, who frequently posts about her parenting journey on Instagram.
“My one outing today was a success. Elle slept through lunch, which meant I got to eat my lunch. #winning 👏👏👏 ,” she shared earlier this week.
Many of Anna's fans followers remarked that this was a moment to savour as a first-time parent.
“How good is it when that happens, good tiny girl Elle 💕💕,” one wrote.
“Parenting win 👊🏼 🙌 the simple things ☺️,” said another.
Anna also kept it real with her social media followers throughout her pregnancy.
During her third trimester, the season one Bachelor winner confessed: "It’s definitely been a love/hate relationship with my body whilst pregnant but I’m getting there."
She confessed that ahead of Elle's birth, she was feeling a mix of emotions about becoming a mum.
"Feeling excited and nervous as all hell," she wrote.
Anna and Tim, 38, announced Elle’s arrival on via social media.
"Introducing the newest addition to our family 🖤," Anna captioned her post.
Meanwhile, Tim penned: "I've fallen in love twice all over again with these two!!! I just LOVE LOVE LOVE 💕 our little Elle Robards 💗How bloody amazing!!!! I never knew my wife was a superhero... What a woman!!"