After watching the movie, there are some parts of the plot I don't understand.

WARNING: "spoilers" spoilers below
Why did the leader of the women want hold the girl hostage so badly, and keep her alive and around? What did she have to do with anything?

And why did the old crippled man want her kidnapped as well? It is part of a revenge plan, of losing his wife, from what I could tell, but what does keeping a kidnapped girl hostage, have to do with revenge over losing your wife though?

Unless I missed something?