If only I understood it better. My grandma has a new match that is also an X chromosome match so I looked to see what other matches they had in common. Milton is the X chromosome match, they have Van Roland and Wilbourne in common. They all overlap on chromosome 3, suggesting this segment is inherited from a common ancestor.
It turns out Wilbourne is also an X chromosome match. I had to drop the centiMorgen threshold all the way down for the X chromosome segments to show.