Righteous women - class 5

[Miriam8]

Regarding what Rebbetzin Heller said about Rivka still being a besula at age three, that in her depraved society this was not normal, well, I was just wondering why the gemara talks about the Besulin returning to a female if there was Bi'a before age three - if this was unusual that there would be bi'ah then, why would the gemara talk about it? Also, why would the halacha be that there should not be negi'ah or yechud with girls after the age of three if this only takes place in a "depraved" society? Maybe I am not understanding what a depraved society is? Why should we be choshesh for depravity if we are Torah-Observing people? Does depravity mean a lack of Torah, and that if we don't follow the Torah, then we will fall into disgusting acts? Or is it that Hashem created us with certain drives, and that we are to control those drives - but if there is a society that lauds those drives as virtuous, they are depraved?
Just trying to understand the connotations of the concept!
Thanks so much for all your wisdom and Torah!!!