For more elucidation of our purpose as yoatzot, see Rabbanit Henkin’s articles: Yoatzot Halacha: Fortifying Tradition through Innovation and New Conditions and New Models of Authority: The Yoatzot Halacha . Dr. Joel Wolowelsky also wrote about us recently in Tradition.
Tzniut can be subjective. On the one hand, aside from a rabbi or doctor, women do not discuss their intimate bodily functions with any men but their husbands. On the other hand, the rabbi is a professional who does not take a prurient interest in these questions.
Halacha is rarely black and white. Personal factors can prove decisive. Asking an anonymous question via envelope limits the give and take between questioner and rabbi. Information relevant to the halachic decision may not come to light. How deep a decisor’s knowledge of a questioner should be is hard to quantify. Sometimes limited anonymity, such as in a phone call, can help questioners open up.
Traditionally, Jews address their halachic questions in all areas to rabbinical authorities. Questions in taharat hamishpacha are attested to in the Talmud (for example, Niddah 20b) and alluded to in the Torah (Devarim 17:8).