This is a good question. All of these women had some effect on Scout, but the one who had the most effect was probably Calpurnia. The reason for this is that Calpurnia was with Scout more than anyone else because they were in the same home so often. In short, Calpunia was a surrogate mother to Scout. Listen to what Atticus says about Calpurnia and her relationship with the children:

“Besides, I don’t think the children’ve suffered one bit from her having brought them up. If anything, she’s been harder on them in some ways than a mother would have been... she’s never let them get away with anything, she’s never indulged them the way most colored nurses do. She tried to bring them up according to her lights, and Cal’s lights are pretty good—and another thing, the children love her.”

So, from a broad perspective, Calpurnia has guided Scout. Here is a more concrete example. 

When Walter Cummingham came to dinner and he doused his plate with syrup, Scout protested and called him out on it. In other words, Scout did not act like a lady or a good host. At this point, Calpurnia is the one who corrects her:

When she squinted down at me the tiny lines around her eyes deepened. “There’s some folks who don’t eat like us,” she whispered fiercely, “but you ain’t called on to contradict ‘em at the table when they don’t. That boy’s yo’ comp’ny and if he wants to eat up the table cloth you let him, you hear?”

Throughout the novel, Calpurnia would exercise her authority over Scout and guide her in her development. 

I know that some might say that Miss Maudie had a bigger influence, but I would disagree. The main heart-to-heart talks that Miss Maudie had in the novel were with Jem, not Scout. 

Finally, it does seem that young women (and men) today have fewer constraints. Considered in a historical view,  think about Maycomb compared to today. One of the main features of Maycomb was that no one left town but today people are very mobile. Then, everyone knew everyone else. In this historical context, there were bound to be more constraints.