Gender Mixing (2)

Sometimes a quick exchange communicates more effectively, and more personally, than an article. Sometimes, just seeing that others share our questions can make us feel more connected. Our posted questions and answers are an opportunity to learn from each other. Keep in mind that each questioner’s situation may be unique, in ways that affect the halachah. Even the tone of a question can affect the tone of an answer.
Curious to understand the reasoning behind saying males and females above bar and bat mitzva age should sit separately when it comes to siblings, in your discussion of prayer as a family at home. (Here.)
We've been davening together as a family? Do we need a mechitza?