ETA: You may have noticed she handles herself a lot better in the later two. The paralysis I'm talking about occurred when he and Phil got lost in the woods a few years later. She sort of fell apart because she just couldn't handle thinking about life without him.
It's Strip number One.
Panel 1: JSF tells Elly that he has to deicde how much insurance he needs to get on his equipment; he switches from that to saying he has to protect against illness or accident.
Panel 2: He then asks her how much he should insure himself against death or dismemberment for considering their yearly expenses. He wants to make sure his family is provided for if he goes because he's too vain and chauvinistic to consider the option "Wife gets a job and supports family in case of his death or disability."
Panel 3: Her response is to weep openly and loudly. Is it because of his cold-blooded, matter-of-fact way of discussing his own passing and/or mutilation? His lack of faith in her? Who knows?
Summary: That's because the punchline is that he's a morbid jerk who doesn't care about her feelings. The notion that he's being a sensible person worried about something real is lost on Lynn. Figuring out why this might be will take all week.