I don't think the abuse charges held water........The defense had a blond wig and a platform shoe on the stand and Mary testified that he made her "do things" she felt uncomfortable with. She said he hit her once. You can read her testimony at the link above.
She also testified that he placed his hand over the baby's mouth to get it to go back to sleep and this was the straw that sent her over the edge. The problem with this is the coroner testified that Matthew had 1000ml of urine in his bladder, and that 200 ml gave the urge to urinate, and at 500 to 600 ml there was a very strong urge to urinate. If Matthew got up, he would have had to pee so bad he would have emptied his bladder.
The check kiting, IMO, is far more likely the reason she killed him. He found out, was mad, she thought she was going to loose her kids and she killed him while he lay sleeping in the bed.
Matthew Winkler was a second or third generation church of Christ Minister. The church of Christ is Fundamental. I'm fairly certain that he believed in traditional roles in a marriage. IMO, he probably had a strong personality who saw himself as the head of the household and the family leader.
If she was abused, why didn't she call her dad, or his dad, and have them come get her.....or, why not just leave?