The Wife of Bath's Prologue

So I have read the Wife of Bath's Prologue, and I thought it was dark. As I was reading along, I was picturing her in this dark world because of the things she have done. She was explaining to people how she's an authority in the marriage, and how she married first husband at the age of 12. I don't get that!!! Was it a traditional thing to get married at that age, or she didn't want to be alone? In case, I felt that she used her men as her sex puppet just to get what she want. I also think that she used the Bible as an excuse for what she does like if the people can marry more than 1 person, than so can she. I don't understand when she stated at line 26, " God bad us for to wexe and multiplye." Now that part is similar to the one in the Bible. But in the Bible, doesn't that saying mean to make children instead of having a lot of husband? Well at this point, the Pardoner stepped in because he is planning to get married and what's bothering him is that he thinks that his wife will control his body. So the Wife of Bath told him her tale to see if it would tell the truth about marriage. I want to know why would she talk to him about marriage and she's the one who's treating her husbands like slaves? She's telling him how out of her five husbands, three of them are good and two of them are bad. The three she explained were rich and old, but admits to put them through hell by making them work. What I thought was funny was when she got hit on the head by her husband because she accused him of something stupid (I guess she wanted attention), so she ripped three pages of a book and hit him on the cheek and he didn't like that, so he just hit her.