What about carbon monoxide poisoning in her office at work. It’s right outside the end of the car wash tunnel…right at the part where they have to re-start the cars and leave them running for a few minutes. Maybe the there’s an exhaust fan overhead that’s running to close or in a shared chase as an HVAC vent for her office…Maybe something springs a leak and poisons her over the course of the day…
It would make sense, no one would suspect anything, Saul would clean up any loose ends and sell the business.
BTW, Skyler can’t flip can she? She doesn’t know enough, right? If she even tried, I think she’d wind up jailed for laundering, but doesn’t know anything other then that Walt is a meth dealer. Does she even know that he cooks? She called him a dealer last night.