Fans were quick to gush over the angelic photo, with one user commenting, "Beautiful ❤️ life is never the same again, and for the better."
Another added, "And a magical Mumma you are ✨"
Alex welcomed Maxwell into the world with fiance Carson Jory back in August, after which she announced his arrival via social media.
"20.08.21. 3.20pm. Maxwell Keegan Jory," she penned in the caption.
"His entrance was intense and it was beautiful. We are so in love."
Alex, who won Richie Strahan's heart on season four of The Bachelor and later appeared on the second season of Bachelor in Paradise following their breakup, first announced she was expecting her second baby earlier this year.
"I wonder if you’ll have your Father’s eyes? Will you be stubborn like your Mother? See you soon little darling," she penned, along with a stunning black and white image of her bump.
She shares her 10-year-old son Elijah with her former boss, but this is her first child with Carson.
WATCH: Alex Nation shows off engagement ring
The reality star went "Instagram official" with her new beau at the beginning of December last year.
Alex introduced him to her followers in a series of sweet photos of them together along with the caption: "Nice to meet you Mr Jory."
Following the birth of Maxwell, Alex revealed that Carson had asked her to be his wife.
Friends and fellow Bachie stars were quick to flood the comments with well wishes, with Laura Byrne writing: "Congratulations beautiful."
Angie Kent added, "How magical! So much love to you and your beautiful little family."
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