Mjkacmom - what a blessing your parents were!
My parents were the local grandparents, I know from my close sisters that my mothers talked about my kids all the time. Now that that same sister has a local two year old extended family member she sees weekly, she makes every effort NOT to talk about him to her far away kids and she realizes It’s just what you are doing and seeing every week so it can be just natural, not malicious, but others can be malicious with favoutism, of course. My sister tells me she used to resent o,ur mom talking about my kids all the time despite understanding it, and now that feeling is easing.
I was the “favorite” but it was because my siblings are much older than me and my black sheep sibling caused incredible stress during their teens, they had different parents than I did. They left home as soon as they could. My parents were tempered by life when this oopsie baby came along, they were better parents to me than my siblings. I was a different kid, no reason to flee, I made all the efforts to be close to them. For example as a young married and with young kids, I orchestrated frequent interactions with them, several times a week. When we moved a day’s drive away, my mother and my SIL both commented that, wow, “sad you are leaving, but now we will have so much time with each other” (unspoken, without you in the way, we two families will get together 
) And don’t take that wrong, I did not, they were trying to find the best in a sad situation. My sibling had joined us for family days, swimming and BBQs, most every weekend, they were not excluded, but much of their time with my parents was created by things I organized. I was a a stay at SAHM the first few years of parents, my SIL had to return to FT work when her baby was 6 weeks old, she did not have much time to organize stuff.
Later, each of them, SIL & mother, complained to me that they never got together. I realized, my mother was not that sort of social person, nor was my SIL, but they each, literally, blamed the other! They did not have people over, they just didn’t craft their lives that way. When we moved, friends who’d come to all our Memorial Day/4th of July/Labor Day, even Christmas Eve/Day parties, none of them had parties or did anything on those days. It was them all coming to my entertaining, but none of them were inclined to create their own social get togethers. Funny!
In summary, that brother/SIL will tell you right now that they did not have much of a relationship with my parents, no problem, but my Mom/Dad never made the effort. Bro/SIL don’t see that they also made no effort. For example, my parents would take the grandkids home from church, bro or SIL would pick them up at the end of a day running errands, but never did dinner. My mother always thought it was weird they did not want to do dinner, but then maybe she didn’t offer well?
My parents, a few years later when Dad retired, moved to our new town. That’s pretty harsh for my brother/SIL. My Dad was so involved with my kids, doing stuff with the schools, including driving, volunteering with a sports team (where he had done a university related sport.) He was lovely and beloved by many local groups. My mother had health issues so did not volunteer as much, but she was a provided a warm, safe, lovely place for my kids to often come after school.
When my parents were failing, over a decade +, I did everything, my brother/SIL did only the minimal and only when I really pushed. I don’t blame them, and my mother never knew their feelings. That brother/SIL are lovely people, we were close when living in the same area, and even now, on the phone we could talk for hours, but she never called me the last 30 years. Now that they are retired they are making efforts to connect, like sending birthday cards and such, all the nieces/nephews/other siblings reaction is that it’s “kinda weird” after all this time, but they just didn’t have the time when they were working, apparently.
People are weird, none of us see all situations clearly. I was the “favorite,” no bones about it, and for totally natural reasons, truly it was not favorite so much as most comfortable. We just spent a lot of time together, so yes, I absolutely appreciated it and am grateful my adult kids miss their grandparents as much as they do whereas the other grandkids mostly didn’t care about little stuff from my parent’s home, my kids and my brother’s oldest, who spent a lot of time with them for her first decade, they all feel super close and miss them in a deep abiding way.
But don’t even get my started on my in laws and favortism, again, I/we did exponentially more work than others, but other kids/grandkids were the more appreciated ones, whereas DH/I/our kids had fantastically high expectations laid upon us and never quite satisfied the in laws desires. 
