Michelle Montgomery was married to Jack Montgomery. After the hunter Travis enlisted Sam and Dean Winchester's aid to observe Jack for suspicious activity in Carthage, Missouri, they discovered that Jack was transitioning into a Rugaru. Travis had killed Jack's father years before, but did not know Jack's mother was pregnant. As Jack developed an increasing hunger, he had to fight hard to resist the urge to eat his wife Michelle when she sliced her finger open. They argued when she had to take herself to the hospital to get stitches. As they were making up, Jack almost lost control again.
When Travis came to the Montgomery's house to use Michelle as bait for Jack, he discovered that she was pregnant with Jack's child. To protect his wife, Jack gave into becoming a Rugaru and killed Travis, completing his transformation. This frightened Michelle, who ran out of the house before Sam and Dean arrived and fought Jack. After Jack knocked Dean out, Sam torched Jack, killing him. Michelle's current whereabouts are unknown.