The comments soon placed their bets as to whether Morgan was having a boy or a girl, with the jury still out.
Expecting mum Morgan also recently took to her own Instagram to share a pregnancy update with her followers.
With her burgeoning baby bump on display, she wrote: "20 weeks pregnant boy or girl? We won’t know until baby is earth side 😊Take your guess 💙💖."
Morgan announced she was pregnant on November 14th last year, sharing the initial ultrasound picture to her Instagram.
"Life is crazy - we might as well stay in the crazy!" she wrote.
"Baby #3 due end of May!"
The fitness instructor already shares two sons, Flynn, three, and Taj, one, with her husband, Ryan Gruell.
Ryan also announced the couple were expecting a third child on Instagram, posting a heartfelt tribute to his family in the process.
"Our family is growing by another," he wrote. "Flynn and Taj are going to share the role of big brother at the end of May when we welcome another Gruell into the world.
"We were so happy to see a perfectly happy and singular baby developing at our 12 week scan.
"True to form to Morgan continues to amaze me with her capacity to love and care for the boys and I (including my FIFO fathering), while also dealing with the fatigue, sickness and soreness that the first trimester has brought."
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