How does Aliza exactly cope wth watching her dad eat meat that belongs to a still living creature from his own kind.

Not well. She kind of has to… ignore it, to carry on. That’s the thing of it, though, it’s it? Why Papyrus lives the way he does. You can’t question the morality of life in the Underground and still cling to sanity, still manage to live at all. Many couldn’t get past it, killing and eating their own. They didn’t make it.