Yes, Freydis does have a baby with Ivar in the series Vikings.
In a significant event portrayed in Vikings Season 5 Episode 18, Freydis gives birth to a son fathered by Ivar the Boneless. This child is named Baldur.
The Birth of Baldur
The arrival of Baldur initially brings a moment of immense joy and anticipation for Ivar, who, due to his physical condition, had previously believed he could not father children. Freydis's pregnancy and the subsequent birth of their son were seen as a miraculous affirmation for Ivar.
Ivar's Heartbreaking Decision
However, this joy quickly turns to despair for Ivar. Upon seeing his newborn son, he is confronted with the reality that Baldur has unspecified deformities. This discovery deeply wounds Ivar, leading to a profound heartbreak and a heart-wrenching decision about his son's future. The impact of Baldur's condition and Ivar's subsequent actions create a tragic turning point in their story and in Ivar's character development.