How does Meggie in The Thorn Birds relate to Scarlett O'Hara in Gone with the Wind?

Both of these characters are women whose rebellious nature make their lives and relationships difficult. They both engage in behaviors that are seen as socially unacceptable and damage their reputations in this way. They both also experience various tragedies in their lives that cause them to develop skills of perseverance.
Both Scarlett and Meggie are extremely attractive women whose beauty is legendary in their communities. Growing up beautiful leads to them understanding the effect their beauty has on men, and they learn to develop their charms in order to manipulate others. But this manipulation is much more conscientious in Scarlett than it is in Meggie.
Scarlett has a more pronounced sense of entitlement than Meggie does and believes she deserves to get what she wants. She was raised within the antebellum South in a wealthy family and so was coddled and praised and taught to be very feminine. Even though the man she loves, Ashley Wilkes, is engaged to another woman, Scarlett insists on continuing to try and seduce him. She even contrives to be alone with him in an inappropriately intimate way after he is married. Scarlett is well aware of the impact of her feminine wiles.
Meggie's inappropriate behavior, on the other hand, is mainly caused by her innocence and lack of experience. Her mother, an old fashioned Irish Catholic, didn't bother to tell Meggie the facts of life, and so when she experiences her first menstrual period, she is afraid and ends up confessing her fear to the parish priest, Father Ralph, who is embarrassed. The two have a close relationship, and he is there as a friend to her as she grows up. When Meggie gets a bit older, Ralph is captivated by her beauty, and Meggie senses that she has a hold on him and tries to seduce him, despite how inappropriate this is.
Meggie does not have the sophistication Scarlett O'Hara has at the same age, because she is much more socially isolated and is raised within the confines of a strict Catholic family. But because of her limited experience, Ralph is the only man she is close to apart from her family members, so he is almost like an experiment for Meggie. She also loves him, but her idea of love is rather juvenile and romantic at first. Meggie's attempt to seduce Father Ralph parallels Scarlett O'Hara's behavior when she tries to seduce an engaged man. But for Father Ralph, having a sexual relationship as a priest is forbidden, so the implications go beyond impropriety to being morally dangerous and sinful.