Mom Welcomes Fourth Baby — Who Shares the Same Birthday with Her 3 Big Sisters: ‘Blows My Mind’ (Exclusive)

"We really can’t grasp the concept ourselves," Kristin Lammert tells PEOPLE

• Kristin Lammert, 35, gave birth to Valentina on Aug. 25, one month earlier than expected

• Valentina's older sisters — Sophia, 9, Giuliana, 6, and 3-year-old Mia — were also born on Aug. 25 and three years apart from each other

• “It’s miraculous that she’s here safely, thriving and growing as she should be,” Kristin tells PEOPLE about Valentina

Not one, twice or even three times — South Carolina mom Kristin Lammert now has four daughters who all share the same birthday, a streak of luck that should be almost impossible.

Lammert, 35, became a mother again with the arrival of her latest child, Valentina, on Aug. 25, who was born one month ahead of schedule.

Lammert's other three daughters — Sophia, 9, Giuiliana, 6, and 3-year-old Mia — also have Aug. 25 birthdays like their new baby sister. Lammert calls it an astounding coincidence.

“The birthday of my dog that I had growing up was Aug. 25,” Kristin tells PEOPLE. “Then 10 years later, Sophia was born and we thought that was so cool. When Giuliana came, she was a little bit early. And when Mia came, she was extra early. Now Valentina’s extra, extra early. We really can’t grasp the concept ourselves.”

Related: 3 Sisters Who Were Born on the Same Day 3 Years Apart Celebrate Their Birthday: 'So Excited'

The odds of having four girls born on the same day is 1 in 1.285 billion, according to Lammert.

"It's not very common at all," Dr. Megan Gray, an OB-GYN at a hospital where Lammert previously gave birth, told Good Morning America in 2022. "Even when you try to time that, that would be logistically very difficult. So it is pretty wild that she's delivered ... children, naturally, unplanned, on the same day and years apart."

Lammert tells PEOPLE now that "none of the four births were planned, none of them were C-sections, none of them were supposed to supposed to happen that way.”

Originally, Valentina was expected to be born on Sept. 25, according to her mom. Both Lammert and her husband, Nick Lammert, 36, didn’t tell their three girls — all of whom were born in Florida before the family relocated to South Carolina — that they were going to have another sister until April, due to concerns about potential abnormalities with the unborn baby.

“We wound up having to do a lot of extra testing and everything wound up being okay,” says Kristin. “But to protect our children's emotions, we didn't tell them until Easter. At that moment, Sophia said, ‘Oh, she's going to come on her birthday.’ I said, ‘Sophia, I really don't want to disappoint you, but she's really not going to come on your birthday. There's no way she's going to be over a month early.’ "

Sophia, however, was certain, Kristin recalls: "She said, ‘No, she will. She's coming on my birthday.’ She was super adamant about it from Day 1.”

Fast-forward a few months and Kristin was getting through her last day of work on Aug. 23 when, while staring at her computer, her vision started to get blurry, she says.

Concerned, she texted a neighbor, who is a labor and delivery nurse, about her growing loss of sight. “She said, ‘Go to the hospital immediately,’ “ Kristin says.

Related: Mom Welcomes Son on Her Birthday, Which She Also Shares with 8-Year-Old Daughter: ‘It Does Feel Wild’

After drawing her blood, the medical staff at Greenville Memorial Hospital determined Kristin had severe preeclampsia, a pregnancy complication characterized by such factors as high blood pressure or signs of organ failure.

“The only cure for preeclampsia is delivery of the baby,” Kristin says. “So they hooked me up to a bunch of things and they were monitoring myself and the baby to make sure I was going to be okay. So they couldn't send me home.”

It wasn’t until about 11:45 p.m. on Aug. 24 that the prospect of having another daughter born on Aug. 25 birthday hit Kristin and Nick.

“My husband and I looked at each other and started cracking up,” Kristin says. “We cannot believe this is going to happen again."

"But we also knew that there was no chance that they were going to allow me to continue being pregnant past the 25th, because at that point she had to come," Kristin continues. "We already knew that they weren't going to let me leave until the baby was born. So if she didn't come on her own, it was going to have to possibly be a C-section. But the chances of them allowing me to stay pregnant an additional 24 hours were slim."

"So," Kristin adds with a laugh, "we were like, ‘Oh my gosh, she's going to also come on Aug. 25."

Valentina, whose name is a variation of the maiden name of Kristin’s mom, came into the world on Aug. 25 at 8:11 a.m., weighing 5 lbs. and 12.8 ozs.,

After giving birth, Kristin was monitored for postpartum preeclampsia as doctors wanted to make sure she didn’t have a stroke, seizure or kidney failure, she says.

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“Other than the fact that she was very tiny, the nurses were taking such great care of Valentina,” Kristin says. “They were all surprised by every marker she was reaching. She didn't need to be in the NICU to learn how to swallow. She didn't have to go to the NICU for her lungs. She was being checked for every single little thing,”

Kristin’s mother brought Sophia, Giuliana and Mia to the hospital later that afternoon to see their mom and new baby sister. A little birthday party was held for the kids in a hospital room decorated with balloons, and pizza and doughnuts were served.

“They were so in love with her,” Kristin says. “My girls kept singing ‘Happy Birthday’ to her, too. Some of the nurses came into the room and we all sang ‘Happy Birthday.' We started at the top: Sophia, Giuliana, Mia — and now Valentina.”

Valentina was discharged on Aug. 26 followed by Kristin two days later because of a medical issue that was later resolved. “I'm not sleeping very much,” she says. “I have to feed Valentina every two hours to make sure she gains some weight because she's still so tiny. But we're doing well.”

Related: St. Louis Newborn Shares a Birthday — and Name — with His Dad and Grandad: 'Incredible'

These days, according to Kristin, any drama in the family is fighting over who gets to hold Valentina next.

“They are just doing a lot of snuggles and spending a lot of time with her,” she says of her eldest daughters. “I'm still having to rest up until two weeks postpartum, which I'm coming up on. But I still am required to be in bed. So we are kind of hanging out in my room most of the time.”

The family is currently taking it easy and not doing many group activities until baby Valentina’s immune system is up; a pediatrician checks in daily on her levels.

“She dropped too much weight,” Kristin explains. “And so we're kind of on a regimen to get her birth weight up. The good news is we haven't had to go back to the hospital for either of us yet.”

The word “miraculous” keeps popping up in Kristin’s mind given what she and Valentina had experienced at the hospital.

“It’s miraculous that she’s here safely, thriving and growing as she should be,” Kristin says. “It’s miraculous that I’m healthy and alive. And then when you throw in the shared birthday factor, that’s miraculous and so unlikely in itself, and blows my mind every time I realize our reality.”

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