Dear Carolyn: My husband and I have a baby, and a toddler niece and nephew. My mother-in-law, "Rachel," is a tough person to handle at times. I am not a doctor and not diagnosing her, but I am a teacher and I believe if Rachel were born today, she would be diagnosed with Asperger's/ASD. I haven't shared this opinion, but it helps me give context to her rigidity and overlooking of social cues. Rachel says she loves her grandkids, but does not really make the effort to connect with them, sometimes (for example) ignoring them to do a crossword puzzle. It really hurts for my husband and siblings-in-law. My sister-in-law asked Rachel to pick a weekend to visit, and Rachel responded, "Well, I have a lot of [plans]," and SIL's face just collapsed and she seemed about to cry.

My father-in-law is a sweet guy but extremely passive. I'd like to say gently that it would mean a lot to everyone if they more actively sought out grandkid time. Any suggestions?

— In-Law

In-Law: Sounds like you’d be talking to the wrong people. Rachel will be Rachel.

So why not talk to the people who are on a hurt-feelings renewal plan every time Rachel lets them down just by being who she is? You don’t need to get into your hunch about Rachel’s wiring. Just: “I see you getting upset when Rachel does X, and I found a way to deal with X that really helps me — are you interested?” And if they are, then you describe your tactics, explaining that you developed them in the classroom. And follow with, “It just may be that you’re asking of Rachel something she isn’t wired to give.”

When someone’s social and emotional limitations are at the heart of the problem, it makes sense to address the problem through the people with some social agility. Rachel may be doing the very best she’s capable of, in which case new, realistic expectations of her could change everything.

Dear Carolyn: Something I realized about myself the other day is that the closer I am to someone and the more I trust and like them, the more sarcastic and dry I am toward them. My default setting is extreme dry humor, but I'm not going to go to my default setting unless I trust the person can handle it.

But . . . am I really just a glass bowl?

— Existential Crisis of Sarcasm

Existential Crisis of Sarcasm: Maybe?

Why don’t you ask. “I go over to the snark side only when I trust people, but it occurs to me maybe I’m just punishing the people who care about me the most. Is that how you see it?”

Your “letting people see the real me” does sound suspiciously close to “putting up defenses just as I’m getting close,” so I’ll throw this out there to dot the i.

Re: Hurtful, not dry: When I'm about to say something wildly amusing but kinda mean, I offer my husband the option of the good answer or the evil answer. That way it's really clear that the evil answer is "supposed to be" funny.

— Good and Evil

Good and Evil: Sounds good to me, thanks, though my rate of choosing the evil answer would probably near 100 percent, so take that into account.

Write to Carolyn Hax at tellme@washpost.com. Get her column delivered to your inbox each morning at wapo.st/haxpost.