Myra, the good twin?

Myra, in The Mineola Twins, although depicted as promiscuous, actually seems like a caring person. In the first scene, she has a nightmare about an atomic bomb, and her instinct is to go and find her sister. After Myra and Jim sleep together, and Jim begins talking about wanting more to life and rethinking marriage, Myra genuinely seems concerned that Jim wants to and will marry her sister. Although Myra has a skewed sense of right and wrong, she ultimately wants the best for her sister.