1. Sword Girl and Quiet Girl are mysteries you can only solve in Act Three. Youre done with them for now.
2. Can't be done in Act Two (MC has no reason to free Dhena).
3. You need kids from more girls. Group events are tied to specific combinations of specific children.
4. Council Guardian's events will be in Act Three. The fishgirl you can move to the Marina once you own it and have met both fishgirls.
Hope that helps! :)