Sadie Adler is a widow rescued by the Van der Linde gang in Red Dead Redemption 2 (2018), after the O'Driscolls kill her husband Jake. She becomes one of the gang's fiercest fighters, then a bounty hunter who recruits John Marston in the epilogue. She survives the game. Alex McKenna plays her.

Raised in the mountains, Sadie could ride, hunt and shoot, and worked her farm alongside her husband Jake. The O'Driscolls killed Jake while she hid in the house. In chapter 1's Outlaws from the West, Arthur, Dutch and Micah kill the O'Driscolls at the Adler ranch and save her. She defends the camp at Shady Belle, keeps the rest of the gang moving with Charles while Arthur is in Guarma, helps Arthur free John, watches Colm O'Driscoll hang, and helps rescue Abigail.
In 1907 Sadie is a bounty hunter and recruits John. She tracks Micah with John and Charles in American Venom, where she is stabbed and taken hostage by Micah, but survives.
She attends John and Abigail's wedding, then leaves, talking about heading to South America. Her future is not shown.
The rest of the gang, with their actors, is on our Red Dead Redemption 2 characters page, and every mission on the missions page.