The black-and-white photo shows Billie sitting on a sofa cradling her nephew, who is wrapped up in a blanket, with only the back of his head on display.
Billie Faiers shared a picture with her "precious" nephew
"My beautiful nephew's evening out to aunties for dinner… You are so precious to me my little darling I love you so much…" Billie wrote. "@samanthafaiers1 I am so in love with being an Aunty to this little pickle… Loved our cuddles this evening."
Sam welcomed her baby boy – her first child with boyfriend Paul Knightley – on 29 December, and announced the news with a photo which showed the proud parents holding the newborn's little hand.
"Welcome to the world our beautiful baby boy 29.12.15," she captioned the photo.
Sam Faiers welcomed her baby boy last week
Billie was one of the first people to congratulate the new parents, and said she couldn't wait for her daughter Nelly to spend time with her new cousin.
"I am the proudest sister and auntie in the world @samanthafaiers1 and Paul… I cannot describe my love for my beautiful nephew… I love you all so much and I can't wait for all the wonderful time we are going to spend with him and Nelly…" she wrote alongside the photo shared by Sam.
Sam has yet to announce any further details about her baby, including his name, but appears to be loving motherhood judging by her social media posts. "Waking up a mummy on my birthday is the best Present anyone could ever wish for," she tweeted as she celebrated her 25th birthday on Wednesday. A few days later she added: "So in love, words can't describe."