HELLO, CAROLYN: My in-laws live nearby and have been a wonderful part of our lives since the day we married. Help with the house — Dad was there. Help with the kids — Mom was there. You could say I won the in-law lottery. My wife and I always expected we would return the kindness when they needed it, to the point that we've passed on promotions requiring a relocation. My in-laws are now in their 80s and Dad has Alzheimer's. Mom is near exhaustion from caregiving, and I now see a patient, sweet person snap at him frequently. We're at the point where my wife and I should be pitching in. I'm over there often to fix broken stuff, do heavy cleaning, etc., however it appears my wife's expectation of "helping" consisted solely of driving them to appointments and grabbing meals — needs that rarely pop up. I think Mom needs regular breaks. I've suggested to my wife that she pick a time every couple of weeks to work from her parents' home and give her mom a few hours of free time. Those suggestions have been met with bluster and no action. I'd gladly do it myself, but my wife will resentfully insist on going in my place. Wife and I communicate well, but this situation presents some novel challenges.
SON-IN-LAW: I could say they won the in-law lottery. Good for you.
This veers into no-good-son-in-law-goes-unpunished territory, but I suggest you gladly do this yourself anyway — and when your wife tries to go resentfully in your place, insist this is what you want to do, solo. Then go. Own this fully as your labor of love, not as hers that you're heroically covering for her.
I have two reasons for suggesting this, one straightforward and one more calculated (for a good cause, of course).
The straightforward reason is that you're the one who deems this important, and you incurred half of this parental debt of gratitude anyway, so, just go repay it. Go give Mom these breaks.
The calculated reason is that it's possible, given your wife's bluster, she's having some emotional, dread-based paralysis. This is heavy, stressful caregiving and it's her dad who's slipping away, which can make the stress even worse. Some reflexively rise to an occasion like that, as you and your mother-in-law apparently did; for others, the reflex is to recoil from it.
In those cases, though, time and exposure and familiarity can gradually coax someone out to help. So if your wife is just balking, then your taking the lead and getting the routine established might be the nudge she needs to do this sans resentment.
Or not, in which case you keep doing it because it's the right thing and you're the right person for the job, which frees her to find a better role for herself. She might be the right person to, say, vet and hire professional caregivers, pay bills, manage schedules, wrangle insurance. There's typically a lot more work for everyone to divvy up before you start to have less.
Even if she never matches your effort here, it's still better to have the "wrong" person step up than no one at all — right? Envision how you'll feel about your choices when this is behind you, and make them from there.