The former Olympian then posted a delightful follow-up message, which features a carousel of candid snaps of herself and her newest family member, Taj.
“IT’S A BOY,” Lisa wrote alongside several love hearts.
“Taj Grant Gruell arrived safely into this world last Thursday, 5th November 2020, 8lb 4oz (for the oldies like me who can relate better to pounds!!)
“A beautiful second son for my Morgan and Ryan and little bro for Flynn .... baby spam coming. Congratulations Morgan, Ryan and Flynn,” she added.
Among the collection of sweet snaps in a photo of Taj snuggling up to his doting grandmother, who smiles sweetly for the camera.
A follow-up snap shows the infant lying in front on his older sibling, Flynn, who is casting a loving gaze towards his grandmother.
Another photo shows Lisa proudly posing with Morgan, Flynn, 2, and Taj, while a final snap again shows the former Olympian cradling the infant, who is napping on her chest.
Enthusiastic fans were quick to comment on Lisa’s happy news, with one person writing: “Congratulations to you and your family .....two beautiful grandsons, how beautiful.”
Another person stated: “Congratulations!! Another beautiful boy! Enjoy those baby snuggles.”
A third person added: “Congratulations granny, he’s absolutely gorgeous.”