My first thought also, when I saw the news, was she caught him with the church secretary or choir director (male or female) or he was abusing her or the kids.
Happens a lot.
At any rate, I feel so sorry for those poor kids.
Or maybe its not his fault. She plainly stated she planned the murder right up to the day she was going to do it. Maybe she's physco. She looks like it. People who knew her well said she doesn't look like the same person they knew. Like she looks kind of wierd.