AITD for calling my little sister rude for leaving our friends wake early to see her boyfriend
Hello Peaches! Not sure if I'm the drama here.
I'm Magpie, he/him 18m. Little sister is "Flamingo", she/her 16f. Little brother is "Crow", he/him 14m.
We recently lost our friend "Robin", he/they 13m. He died from heart failure about a month ago. He was Crows best friend, and a close friend with the rest of the family. I've known him for 9ish years, maybe even 10. Their family are all scout leaders, our family are all scout leaders, and anyone who's familiar with scouts (at least in the uk, cant say for the rest of the world) knows that scouting families tend to be quite close with eachother.
Yesterday was his funeral. There was first a ceremony in one place, the place was packed and there were so many people that half had to stand. It was beautiful and heartwarming and I cried quite a bit. My little brother clung to me and my sister the entire time, and we held back because it's an awful thing to go through, especially so young. Then there was a second ceremony elsewhere, a goodbye before Robin is cremated. At this one all the scout leaders of the district turned up in uniform to say goodbye, and his necker was laid on his coffin. My brother sat with his friends in this one, all of them friends of Robin
Next came the Wake. The wake happened to be close(ish) to my sisters boyfriends house. They've been dating two months, maybe less? She's quite secretive about her partners and they come and go quickly. Anyway, he'd been on holiday for about a week so she hadn't seen him for a week, so as soon as she arrived at the wake she contacted him. At the time my brother an this friends were panicking and upset because the wake was "welcome to everyone" and bullies of Robin had decided to turn up and laugh/take photos of grieving people and the photos of Robin on a showreel (they left within an hour after numerous attempts by actual friends of Robin to tell adults to kick them out). 5 minutes into the wake, my sister announced she was leaving to go to his. It felt really early to be going, and whilst my brother was upset too? I also asked Flamingo if she was going to write a memory of Robin in the memory book his parents had put out, and she told me she "can't be arsed, can you write something for me?". So I wrote something for us both. But it felt incredibly rude.
Later my brother said he had noticed Flamingos absence at the wake and he said it had been quite upsetting. I messaged her (whilst she was still out at her boyfriends) that I felt it was rude, how she left so soon and couldn't even wait to write in the book (which didnt even have a queue when she left, i was just about to start writing). Yes, she hadn't seen her boyfriend in a week, but she's never going to see Robin again? She read the message but didn't respond. She got home after I went to bed and I think she's still in bed now so I haven't seen her since the wake.
AITD for calling her rude?
Edit Update: Me and my sister are on completely normal terms again, I'm guessing she assumed that I was upset in the moment and we haven't spoken about what I said. Thank you everyone for providing other perspectives, I see now that I shouldn't have said what I said and understand that she was processing differently