On Monday, the rapper, 34, shared a birthday tribute to his girlfriend's daughter, Namiko Love (who goes by the nickname "Nami"), on his Instagram Story in celebration of her 14th birthday.
"Love you Nami! You're one of the smartest, coolest people on 🌎," he captioned the shot where the two pose together as Big Sean holds newborn son Noah Hasani.
"My anime plug and newly big sis! This world is a much better place with you in it! Big 14!" added Big Sean.
The newly minted mom of two, 34, also shared a birthday tribute for her teen, writing, "Happy Birthday Namiko! 🥰 the most beautifulest girl in the world 😍."
Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
Renee Rodriguez │ @byreneerodriguez
Celebrating her daughter as "the coolest person I know 😎," Aiko raved about her "animal loving, actress, anime expert, rockstar, skater girl, artist."
"I'm so proud of everything you are 🥲 you may be 14 today, but you will always be my baby I love you!!! 💙," she added.
Aiko and her rapper beau welcomed their first baby together, Noah on Nov. 8, according to an Instagram post the singer shared.
"✨11/08/22✨💙Noah Hasani💙," she wrote alongside the series of pictures. "After 24 hours of labor, a total lunar eclipse, and while it was pouring rain… he came my baby Yoda, my Sani 💙."
Jhené Aiko Instagram hené Aiko and Namiko Love
In early July, PEOPLE confirmed that Aiko was expecting a baby with Big Sean. "The couple is overjoyed and looks forward to this next chapter," Aiko's rep told PEOPLE.
Aiko and Big Sean first met in 2012 and developed a close friendship, collaborating on several songs together before releasing a joint album, Twenty88, in 2016. While doing publicity for the album, the pair's chemistry became apparent, with the rapper telling Billboard, "I love her and I know she loves me." They have dated on and off in the years since.