Birthdays and assorted crap

I found out today, just how bad my cousin's health is. She's my one female cousin on that side, she's had a miserable life, and now, she's got at most six months to live.
Fuck.
She was my favorite cousin, which is what makes this suck all the worse.
The reason I'm even more pissy? My grandma brought all this up during my sister's birthday supper.
Yeah- we don't get together that much to share information. But while my grandma was trying to talk about how many little miracles were going in in my cousin's life, my dad started to talk about how painful a death cancer was. And they just kept talking about it. And my sister was about to cry.
So I told them they were being extremely inconsiderate and to please change the subject.
I'm not sure who made me more annoyed- my dad or my grandma. I love my grandma and I'm probably going to lose her soon. Death happens, crap. But its a birthday celebration. I don't care if its a lie, a thin veil of daydreams... Let's try to pretend its happy. Don't talk about shit like that.
Honestly, I'm more mad with dad about how he kept going with the 'dying painfully' shit. We KNOW its hell. Please to bring it up. There's nothing we can do about it. I can't save my cousin or her two boys. I can't even go and talk to her.
But I'll be damned if I can't help someone have a good birthday.
I honestly don't know if I helped or not. I think my grandma's feelings were hurt- though I was glaring at my dad the whole time. I don't know if my sister appreciated my attempts to help or not.
But I know I at least tried. I tried to help. I think that means something.