"On the morning of February 2nd, our little girl joined us earth-side and we will never be the same. We are all as healthy and happy as can be," Bekah captioned a photo on Tuesday in which she was holding her newborn while sitting inside of a bathtub naked.
Grayston initially shared the couple's exciting news on Instagram by sharing two photos of his daughter.
In the pictures, the baby was sleeping on Bekah's chest with little gray mittens on her hands.
"#nopicturesplease," Grayston captioned the post.
In July 2018, Bekah revealed she chose not to appear on Bachelor in Paradise's fifth season because she had met a man, 29-year-old Grayston -- who worked at the rock-climbing gym where she climbs -- in February.
Two months later, 23-year-old Bekah shocked the world by disclosing she was 20 weeks pregnant at the time and the pregnancy was unplanned.
Bekah revealed to PureWow at the time she had learned she was expecting a baby only three months into her relationship with Grayston.
"I was in disbelief and thought, 'Is this really happening?'" Bekah said last year.
"I immediately called Grayston and then went across the street to the Dollar Tree and bought two more pregnancy tests. They, of course, were both positive."
FOLLOW REALITY TV WORLD ON THE ALL-NEW GOOGLE NEWS!
Reality TV World is now available on the all-new Google News app and website. Click here to visit our Google News page, and then click FOLLOW to add us as a news source!
Days before delivering her baby, Bekah took to Instagram with a baby-bump photo and discussed her mental state.
"39 weeks + 5 days. I actually have super-human patience right now," Bekah wrote alongside the picture last week.
"I know my due date is [February 5], but I am perfectly at peace with going a couple weeks more. I trust my baby and I trust my body. He or she will come when they're fully ready for the journey earth-side."
Bekah was all smiles in the photo, as she was wearing a ruffled white crop top and blue tassel earrings.
Bekah made it to Week 7 of The Bachelor competition in 2017. Although she had incredible chemistry with Arie, the 37-year-old pro racing driver appeared concerned when she told him about her age.