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.
"Happy anniversary my soulmate! I am so grateful to have you in my Life and the Love that you share with me reminds me of what should be nurtured and fought for in Life.
Thank you for being dedicated and loving mother, big support and backbone to all of us close to you. Love you with all my heart and soul ❤ " the caption of the above photo reads.
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:
This article originally appeared on Who