According to Halacha, at what age does a girl need to dress Tznius, i.e. that uncovered parts are considered Erva?

Three years old.   Sources: בחי׳ הרשב״ץ ברכות כה , … Continue reading According to Halacha, at what age does a girl need to dress Tznius, i.e. that uncovered parts are considered Erva?