Would you arrive empty handed?

I need to let this go, but I also need to let it out first!

I invited Paw’s brother and two sisters to lunch on Sunday as it is one year since he died and I thought they might wish to visit his grave.
It took a week before I actually got a response (Saturday afternoon) but luckily I always have the wherewithal in the freezer to put a Sunday lunch together.
Fine.
I’m not bothered on my own account but I was brought up (and I know they were too) to always take something small, flowers, chocs or a bottle -depending on who you are going to, as a gift . In German they call it a “Mitbringsel” -literally a little thing you bring. .
So no flowers for me apparently, no wine, fair enough, they are family, I thought, but when I suggested we walk up to the church to their brother’s grave I expected somebody to say Oh I’ll get the flowers from the car.
????
Nope. Nothing, Zilch. Nada
I am too chicken to say anything and I was too slow to say “innocently” “oh have you left the flowers in the car?”
When we got there they would have seen the pink roses I took on Saturday and the white roses DD laid on his grave when she came to stay. Did anybody say anything?
Did anybody hug or talk about him?
I know his sisters loved him but I was so disappointed at this lack of a gesture either to me or even to each other.
When they left I wished them a safe journey, asked somebody to text me to say they were back or expected to hear this morning.
Did I?
A text, phone call or email to say Thank you?
Just a bit brassed off frankly. The sisters are very kind women and help DD2 with one day a week childcare between them so I know they are not mean or rude(not so sure about BIL, he only ever thinks of himself) but I know that my own DDs would always remember to say thank you and show their appreciation. And my Mum would have given me more than an earful!
Years and years ago I had an absolute houseful over Christmas, MIL 2 SILs, BIL plus his then wife, Niece and her friend from Brazil, all staying and after they had gone MIL was the only one to drop me a note to say thank you.
???Seething just a bit!
AIBU?