Yes, we can assess the life lived -—that’s an objective thing, open to our view -— and say if she did not repent, she is doomed to lasting horror.
However we cannot say with moral certainty that she is in hell, because it is something we cannot know. She could have repented in the very throes of dying, as did the Good Thief.
Therefore we are entitled -— we are obliged -— to pray for her.
I'm not sure what the Catholic view is, but it's too late to pray for her once she passes on. That die has been cast.