Sorry about all of this. It is always difficult when we lose a pet/fish/friend...
Rule number one of this hobby (and pets in general) is that stuff dies. I know that does not make it easier, but it is a fact. These fish and corals and inverts are "spacemen" that we stick in these capsules and we try to provide the best survivable environment for them. The smallest thing can make it not work out. I have found these lessons important for teaching myself, and my child about mortality, and how to deal with it. I don't even think I could count the numbers of fresh and saltwater fish that have died while under my care over the last 40 years.
It is a choice, and if your wife chooses not to do it, well, then, that is her choice. Let her decide. I wish you both the best.