Plot hole: The local newspaperman points out Miriam to the insurance man before she gets out of the car, and the car is across the street - there's no way he could know it was her before she got out of the car.
Plot hole: In the beginning, Charlotte insists to Velma that cousin Miriam is coming, but Velma says "She's never answered any of your letters." And Drew says she's not coming. But when Miriam does come, only seconds later, Velma and Drew now act like they were expecting her. Velma says "You nearly beat your telegram. We weren't expecting you till tomorrow." It's like the film has been badly edited, with Miriam's announcement of her arrival ending up on the cutting room floor.