Walt now makes a shytload of money when he was previously working two jobs to make ends meet. Walt started to dip out for long periods of time away from the family. Walt's behavior became more erratic (getting Walt Jr. drunk, fugue state, etc.) as time went on. Walt successfully manipulated the situation in such a way that no matter what she does her son would hate her for it. She should just accept that her husband is now a drug dealer without any complaints? Especially considering Walt deals with people who don't fukk with him beyond the blue meth. Hank himself almost got bodied by people who were originally coming for Walt/his family. She has a right to ask questions, when Walt started cooking meth he ended up putting targets on his own family.
On two occasions she almost did stop Walt: when she called the police to their home and when she was with the divorce lawyer in S3. The main reason why she didn't was not really the money, it was Walt Jr.
Since you wanna use examples, Walt was given three outs of the meth game. One was the events from the first episode, two was Gretchen from Grey Matter offering to pay for his treatment, and three was his cancer going into remission. These are signs from fate, God, whatever signaling for him to leave while he still can. He doesn't stop because of a deep-seated rage at his life thus far, pride, and deep down he likes Heisenberg Mode. Had he left at that time
none of the events in S3 or S4 would've happened.
Walt's bout that life alright, but it's his family/Jesse who end up paying for it.