Mechitza (4)

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.
Question
Hi! Until what age can girls daven with their fathers in the men's section? Are there any Halachic sources on this? Is there room for leniency until Bat Mitzvah?
Category:
Thank you for the wonderful site. What is your opinion about women speaking in Bet Knesset. Is there a difference whether she speaks in the middle of Tefila, before Adon Olam, or completely at the end? Thank you!
What's the halacha of mixed swimming in tzanua attire?
What are the varying halachot (and sources) for a mechitza at a simcha? What is the halachic difference between an L-shaped mechitza and one down the middle at a simcha? Also separate vs mixed seating at a simcha?