imagine percy and annabeth's last couple of days at camp half-blood. imagine on the second to last day, they spend the entire time helping each other clean out their bunks and pack their belongings in their suitcases while the other campers go about their day. imagine the couple eating dinner with the campers and then heading to bed at bedtime only to sneak off to the lake later that night and cuddle in an underwater bubble for a while. imagine them sharing a kiss and a quiet 'i love you' as they sneak back into their respective cabins (all of the big three kids sleep in percy's cabin that night, so they definitely tease percy, and athena cabin definitely teases annabeth). imagine the following morning when the couple wakes up and joins the camp for breakfast, they sit at their respective tables (all of big three kids sit at a table together so percy doesn't sit alone like he did when he first joined). imagine the couple going about their day: percy teaching the younger campers the sword-fighting moves that saved his life; annabeth teaching the younger campers that they always have a family at camp. imagine chiron looking upon the two as his best soldiers and trying very hard not to break down at the thought of them leaving. imagine the couple joining the bonfire for a little while before grabbing their suitcases out of cabins 3&6 and crossing the border as camp half-blood wishes them luck out in the real world. imagine it all being extremely bittersweet, but they all know the couple will be back next summer.
I would call that a suicide tbh. I don't think what Penny (or Pyrrha, or Yang, or Hazel,) did counts, since it wasn't "I want to die" and more "I have to die for people to win.".
Ruby wanted to die. Huge difference. As far as she and the other characters know, she pretty blatantly just committed suicide. After being tortured and told over and over and over that the world is better off without her.
Fuck, man. Of all the characters they could have had for a scene like that, Ruby is by far the most gut wrenching.