But then, at around 18 months old, Nicholas began regressing with his speech and motor skills, then refusing to answer to his name or notice people enter a room.
"We had no idea what was going on," the Real Housewives of New Jersey star, who hid her son's medical issues from the reality cameras as she continued taping season 4 last year, tells PEOPLE exclusively.
After an agonizing wait to see multiple doctors, the Lauritas got a diagnosis: Nicholas is autistic.
"I worry about him being independent when he's older," admits Jacqueline, who is also mom to Ashlee, 21, and C.J., 10. "I spend all my time researching what we can do for him."
Adds her husband Chris: "You never want to think that your child isn't perfectly healthy. We didn't want to believe it was true."
For all the details about the autism diagnosis, the Lauritas' struggle to get treatment and Jacqueline's Real Housewives future, pick up this week's issue, on newsstands Friday