What happened to Outlander Jamie Fraser's mum Ellen?

dailyrecord.co.uk:

He's the Highland warrior that an army of fans have fallen in love with after reading the Outlander books and watching the TV hit show.

But what do we know about the woman who was Jamie Fraser's mother, Ellen MacKenzie? Said to have more than a passing resemblance to Jamie and Claire's daughter Brianna, Ellen was the red-haired daughter of a clan chief with a sharp tongue who captured the heart of not only Jamie's father Brian but also that of his godfather Murtagh.Not shown on the show, other than in a self-portrait at Lallybroch, Ellen (unlike her husband Brian) remains a figure from the past when we first hear about her.Set to be the focus of a new prequel novel confirmed by Diana Gabaldon, the romance of Brian and Ellen is almost as fascinating as that of Jamie and Claire.First meeting at the Great Gathering, which was called to decide on Jacob MacKenzie's successor for the title of clan chief after his death, Ellen (Jacob's oldest offspring) was courted by Brian, the illegitimate son of Lord Lovat, Simon Fraser.Secretly eloping over fears Ellen's brother and Brian's father wouldn't approve, Ellen fell pregnant with her new husband's child – Jamie's older brother, William.Sadly William would go on to die at a young age of smallpox, however, their second and third children Jenny (Laura Donnelly) and Jamie would both go on to survive to adulthood.The tragedy also followed with the birth of their fourth child, who was to be named Robert, with both Ellen and the baby dying in childbirth.Outlander official images from season 6 have just droppedThough she died before the events of the show, Ellen left a lasting impression on the characters who had met her.Murtagh in particular worshipped her and even transferred that