Shortly after sharing the news with the world, the new mum gushed over Billie in another Instagram post, sharing two new photos of her baby girl.
“Getting in all the chest cuddles with my little angel,” she wrote in the caption, sharing a photo of herself cradling Billie to her chest while she grins at the camera.
“Haha and how cute is she here?! Second pic, she’s like - “that’s me in there mum”,” she added, with the second photo featuring a close-up shot of just Billie.
Her post also highlights a new locket she received of a “little scan with [Billie’s] legs up” so that Becky has “a piece of her with me always whilst she spends her nights in NICU”.
It comes after Becky’s sister and fellow former Bachelorette Elly Miles shared an adoring post for her niece on her Instagram Stories.
“I was lucky enough to be a birthing partner for my gorgeous sister @happylittlebeckymite and her incredible partner @bevitron last Saturday morning!” she said.
“Witnessing my sister birth little baby Billie was one of the best moments of my life. She arrived a little earlier than planned but she's a tough little cookie and doing so well!!
“I'm one proud Aunty & Sister. Babs, we love you so much already,” she added.
The two sisters have clearly come a long way since their reality TV days, with Becky falling for her partner James almost two years ago on the dating app Hinge.
Speaking with The Daily Telegraph earlier this year in January, Becky gushed over starting an exciting new chapter with James after falling pregnant.
“We have been dreaming of those next steps and talking about engagement and having a baby and now that has all become a reality,” Becky said.
“Although it seems a bit surreal still, it is really exciting, and I can’t wait to be a mum.”