Continuity mistake: After Scarlett overhears the girls gossiping about her, the first "Yee-hoo!" from the men is heard, and Scarlett looks dismayed and about to cry. Her facial expression completely changes in the very next shot; to a sly, queer look.
Continuity mistake: In the scene where Gerald gets on his horse to chase after Jonas Wilkerson, Suellen and Carreen run outside to see what is going on. The door is left open when they come out, but in the next shot that shows Scarlett yelling for Gerald to come back, Suellen and Carreen are no longer outside and the door is closed.
Continuity mistake: When we first see Tara, as well as in the shot where Scarlett is running away from the Tarleton Twins to meet her father returning from Twelve Oaks, there is a very large tree directly in front of the main house. There are two white peacocks underneath it. In all subsequent shots of the house, when Scarlett and her father are talking in the sunset and again when her mother is arriving from taking care of the poor white trash Slattery family, the tree is completely gone.
Answer: If she looked rich she could trick him into thinking she wasn't marrying him for his money.