Thank you to everyone for your thoughts - I have clearly had conflicting emotions about this whole situation, and many of you have picked up some of what has been running through my head.
There are obviously a number of other sister-issues at play here - her behavior while our mom was in the nursing home / rehab for 3 months was horrendous, and completely self-centered. The nursing home was 5 minutes from her house, and 25 minutes from mine, yet I managed to stop by at least 5 times a week, actively engaging mom, while she made it maybe 1.5 times a week. I will give credit to nephew as he did stop by a couple times a week on his own - but he was using his grandma’s car then, she “wanted to make sure it was still running.” But at least he was very careful with her car.
I understand that very few people like to go to graduations, they are boring, and I have been spoiled because S and D did so well.
A big part of me thinks nephew invited us because he wants a graduation gift (which we would send anyway). I really don’t get the impression he is proud of his accomplishment, instead it is more of a sense of relief to everyone involved. He has always been an underachiever in school, doing the bare minimum or less than that. S has told us that he is sloppy and careless in his work, if he does it at all. But he did attend class much more this past year - it was his sophomore year that he repeated due to his absenteeism. While sister brought him to see a doctor about his alleged headaches, she never spent any time with him on his summer make-up work - which he made no attempt to do himself.
I am proud that he did manage to show up enough that he will be able to graduate - I know from my volunteer work that once truancy bites in high school, it is very difficult to overcome.
I am sorry that some of what I wrote initially makes some of you think I have a huge amount of contempt and disgust for them both. I love my nephew and my sister, well she will always be my sister. I won’t ever forget the kindness she has shown my pups when my medical issues flared up. But I think she has taken advantage of our mom, and our late father - whining about her finances even though she earns 50% more than DH does. She complains that college for her older daughter is so expensive because she didn’t get the great aid that my pups have earned. Mom falls for it and gives her money all the time. Mom complains to the rest of us that she has to pay her daughter to get her to come visit her. Of course, mom can do what she wants with her money, but the rest of my siblings agree that sister is taking advantage of her.
I honestly don’t think my sister wants to go to his graduation anyway. Her attitude when he was young was perfectly summed up with a statement she made to us when he was around 3 or so - “I don’t need to read to him - that’s what school is for, they will teach him to read - why should I do someone else’s job?”
Nephew has caused many of his own troubles by the choices he has made, but ever since he was little, I was always bothered about how little attention she gave him. I don’t think I have disgust nor contempt for him, but as his grandmother says, its more of disappointment in how she raised him.
I am of course proud of my pups, but I don’t think I have ever rubbed it in to them. I am more likely to downplay their accomplishments when asked, and I will often change the subject to ask what’s going on with them.
DH has been wonderfully supportive. He told me we should go to the graduation, as he is afraid S won’t even take a picture of Nephew in his cap and gown. He has a point - she did not take a picture of niece at her graduation, the only picture she has is the one we took. Nephew did not attend his sister’s graduation, and his sister is studying in Spain and won’t be back for his graduation.
The reason I wanted to get him a clothing gift card is because he doesn’t appear to have any shirts that fit him that aren’t weed-tee shirts, and I don’t think he’s worn a pair of long pants in four years, since his grandfather’s funeral. DH and I thought about getting him a year’s membership to a local fitness center, but that seems too awkward at best, if not outright insulting at worst.
The other issue is that his grandmother has set a precedent of giving $500 cash for high school graduation - for all the other grandchildren. She would be mortified if she knew he was smoking pot - she thought he lost his license and car because of the accident - she does not know it was DUI, and on the one hand I think it is kinder to let her believe what she wants. But my other sisters and I want to find a way to suggest to her that giving him cash is not in his best interests.