Because you're still alive.

[ She keeps holding the girl, gently stroking her back. ]

People can live past the worst day of their lives. Even someone who has lost everything, for that person... maybe their strength is found with someone new, or something new. Maybe it'll take years, or maybe it'll be instant. Who can say, I can't. But everything, everything is subject to time. Nothing, not even pain, can truly last unchanging forever.