wife hardends heart

[planet]

we've dated about 4 years and are married for 6years with 2 kids. I always wondered why she chose me. She had quite a number of pursuers. She almost left while we are dating but had a change of heart after i gave up pleading and decided to move on. I made promises to change but never really did kept it.
She did gave me a book about relationship she never read hoping i would better myself. I always thought its a bit hypocritical.
We had a fiery relationship. We would argue over something every 3 months or so. the disagreements seemed so petty at times. It always seemed like its my fault or she could be disappointed with me being uninvolved and distant.
There are several incidences involving my mom or her lack of thoughtfulness that really bothers my wife. She felt so unloved by her MIL. It bothers me to find that her mom never really did anything for her when she's pregnant but takes issue with my mom for not being involved. She finds my mom a hypocrite.
My sis was different. She resented my sis for doing something taboo over our wedding period which we had cautioned everybody earlier. She nonchalantly mentioned she's done something after our wedding. My sis strongly denied it when we confronted her years later. My wife never believed her. We don't have any proof other than what she said.
My family and i don't really have much memory of the things that we've so seemingly 'wronged' her.
Maybe her anger is indirectly targeted at me for not defending nor speaking up for her. But to be 'hateful' is really something else. She wanted to insert 'restrictions' in the legal agreement but was refused.
I have to stop putting my logical brain into this in order to empathize with my wife's feelings of rejection. but all of this is so crazy.