Well, I ended up chickening out. :D I realized that Dora was going to die on Saturday, so I figured I'd wait until Sunday to avoid issues.
I was going to send them on a beach vacation with the insurance money from Dora's demise, but everything still got wrecked. I wasn't keeping track of the time and Sharla was due to age up at the same time. I triggered her to age up just as Dora got home from work. Grimmy came for Dora just before Sharla aged up and surprise, surprise - one of her fears was Dora's death. She tanked. After all this time, I finally had a Sim age up badly. The twin toddlers also had fears of a family member's death - tanked! Samantha had her hands full straightening them out. And to top it all off, the insurance company denied the claim! (I guess the aging transition canceled out the insurance pop-up.)
Then, I decided to wait until Monday to invite the Headmaster because David was going to be off to Uni that afternoon and the twins would age up that evening. Might as well catch them in one go so that they would never have to set foot in a public school.