1) A woman's vows are only binding if her father or husband agrees to them, otherwise the vows are automatically annulled and the woman's "sin is forgiven."
2) The Israelites must go back and kill all the non-virgin women of Midian, because the Israelites only killed the men on the first round (virgin women are always spared).
3) Reuven and Gad ask Moshe if they could settle the land on the East of the Jordan, as they've discovered that the land is pretty darn good, and, to them, preferable to living in Israel. Moshe gives them the option of fighting with their brothers and getting the land outside of Canaan that they want, or opting out of fighting altogether, yet getting stuck with land inside Canaan for which their brothers still must fight.
Very strange deal. Very difficult Parsha to relate to. No wonder the Bat-Mitzvah girl decided to read from the Haftarah.