Taking to Instagram story, Jelena, 31, posted a snap of herself breastfeeding the one-month-old.
The adorable picture includes their family's pet dog, Pierre, who appears to be keen for a cuddle.
Djokovic, 30, and his wife became parents for the second time on September 2.
The couple met 12 years ago, married in 2014 and welcomed their son Stefan, 3, in October that same year.
Check out a sweet video of Djokovic and his son below.