Lucille (Smith) Heiden, Minnie Milhan and  Leo Heiden in the 1960s
 
 
Minnie Milhan was the daughter of Carl Milhan who was the brother of Wilhelmina (Milhan) Rambow. Wilhelmina was the mother of Mary (Mrs Wm Carl) Heiden and the grandmother of Leo Heiden.

In other words, Minnie was first cousin to Leo's mother and first cousin once removed to Leo.