I did say, "I can understand her pain and disappointment", but like you said, "That doesn’t give her an excuse to blow his and his new wife’s brains out". I've heard of lots of wives who work to put the husband through school and then get dumped when the going is good.
On the other hand, her husband's lawyer claimed that she was doing good financially and got repaid for her working to help him get his degrees =
{{ Wells portrayed Broderick as a murderer who planned and schemed to kill her ex-husband and argued to the jury that Broderick was not a battered woman. She had, after all, been getting $16,000 a month in alimony in addition to the salary she earned working at an art gallery. She was also living in a $650,000 La Jolla beach-front property that Dan had bought for her, she had two cars, she had a boyfriend who was living with her at the time of the murders, and she currently had her two younger sons living with her.}}
I don't know if that is all true, I got it off Wikipedia =
https://en.wikipedia.org/wiki/Betty_Broderick