The former TOWIE star announced her excited news on Twitter following the arrival of little Teddy. She tweeted: "Going to see my little sister @RiannaGoodger who has just had her baby boy! #littleAngel x"
And it looks like it was love at first sight for the new auntie, as she swiftly uploaded some adorable snaps of herself holding her baby nephew and affectionately kissing her sister Rianna on the cheek.
The tiny tot - who weighed 9lbs 8oz when born - can be seen snuggled up in Lauren's arms and wearing what appears to be a hat and matching blanket covered in teddy bears. Very appropriate!
Lauren captioned one of the photos, "Me and baby Teddy" while she wrote next to the picture of herself and Rianna: "Proud of you @rianna_goodger".
After the birth of baby Teddy it seems a celebration was in order, as the reality TV star partied the night away over the weekend in an outfit that showed off her glowing holiday tan.
Posing for a picture beside her cute pet dog MiMi, Lauren sported a white cropped top and a pair of sparkly silver high waisted shorts.
However, she did admit to feeling a little exhausted at the end of the evening and wrote alongside the photo: "#nofilter me and my boo partied out xx"
Congratulations about becoming an auntie, Lauren!