Fans of the novels by Diana Gabaldon will know Jamie is not the father of Malva's baby but it's someone much closer to home. Allan (Alexander Vlahos) is the father of Malva's child and had been abusing his sibling for many months and when she felt guilty about her lies, he decides to silence her.
Jamie does not sleep with Malva in Outlander
The story comes out over the course of A Breath of Snow and Ashes. Malva makes her story about Jamie being the father of her unborn baby convincing. She shares that she knows about the scars on Jamie's back.
However, Ian really did sleep with Malva—but he was not the only man Malva lay with.
During his time apart from Claire, Jamie slept with several women, including Mary McNab (Emma Campbell-Jones) and Geneva Dunsany (Hannah James). And of course, there was Laoghaire MacKenzie (Nell Hudson) as well who had her sights on Jamie since season one.
Later, after Claire has returned to the Ridge, she is confessor to Allan Christie, who explains that he was the one that fathered Malva's child, and then murdered her.
Malva, before her death, tells him that she made them sick. She'd collected parts of the dead Sin Eater and poisoned Claire and Tom. She wanted to get to Jamie, and getting Claire out of the way was the only way to do that.
The scene also happened in the novel Voyager where Mary told Jamie she wasn't trying to make him forget about Claire but allow them both a moment of solace. Jamie acquiesced through tears, deeply missing Claire. He was so emotional, he had to close his eyes as he slept with Mary.
Jamie denies having slept with her, but the damage to his and to Claire's reputation is done—and the bond between the Frasers and Malva is severed, until just a few weeks later, when Claire finds Malva murdered in the garden. “It's like the peak of the tragedy, and it's so visceral.
Jaime's relationship with Cersei begins to fray. He has loved his twin sister all his life and never slept with another woman. Jaime believed Cersei had the same level of devotion to him, only to learn that while he suffered and fought his way back to King's Landing, she was sleeping with other men.
And then Malva drops the bomb, stunning everyone by declaring that Jamie is the father of her unborn baby. He didn't rape her, she stresses, knowing that that would never be believed, but claims the pair became intimate while he was emotional during Claire's illness.
Claire eventually realizes that Malva is lying because she knows her husband well enough. Tom seems to question Malva's story. You can see it in his face that he's trying to figure out if this story is true. And then there are the reactions at the funeral when Allan refuses to let Claire carry the baby's coffin out.
Malva was first introduced at the beginning of the season as a new resident of the Ridge who admired Claire's medical skills. Behind her admiration was a darker side of blackmail, betraying Claire's trust, and stalking. She falsely claimed Jamie was the father of her unborn child.
Fans are convinced Outlander heroine Claire will be poisoned by Malva after she was seen slicing off a finger of the dead Sin Eater (David Gant) who was introduced in episode two.
Allan began molesting his half-sister Malva from the time she was a young child and eventually, gets her pregnant. She starts sleeping with various men in order to deceive everyone as to the child's paternity.
Mona was sentenced to hang, leaving both Allan and Malva in the care of their aunt.
Over the course of the first season, Claire and Jamie fell in love and married while Frank was back in the 20th Century. It quickly became clear Jamie's ghost was trying to find his beloved which is probably why he was watching Claire.
Claire is arrested for murder, but Tom learns the truth in the end. It was Allan who did it. It turns out Allan sexually abused and raped Malva, and he is the father of the child. He made Malva sleep with other men and eventually claim Jamie is the father.
In the Outlander novels, it's revealed Allan Christie (Alexander Vlahos) fathered Malva's child after sexually assaulting her repeatedly - even if she was his half-sister.
Outlander series
Henri-Christian is born as the fourth child of Fergus and Marsali. He is a dwarf and some of the residents of Fraser's Ridge believe he is a punishment for his parents' sins. Henri-Christian is placed in a basket and put into a stream by some boys. Roger saves him and baptized him.
Jamie: "Claire, it was you. It's always been you, and it always will be. Get into bed and put the candle out.
Tom Christie admits to having feelings for Claire and knows she's innocent, so he confesses to killing his daughter in order to spare Claire's life.
William loses both his mother Geneva, who dies during childbirth, and his supposed father the Earl (killed by Jamie), shortly after his birth, from there he ends up in the care of Jamie's friend and close confidant Lord John Gray - who had married Geneva's sister Isobel.
Director Brendan Maher told Vulture that while both Menzies and Heughan had stunt doubles for the physically demanding sequence, neither used them much. “We had people for safety, just in case, but the nature of the work is that you want the actors to do as much as they possibly can,” Maher said.
The simple answer is no. Claire and Jamie don't have any more children after Brianna. Claire heads through the stones while pregnant with Brianna at the end of the second season/book. She spends 20 years in the 20th century, and she and Frank don't have any children together.