I don't think Lord Hades would let me do it more than once. Especially not if it were actually her time to go, and not...

[ He trails off, staring at the table. Her choice to go, rather than die slow out in the cold. ]

If it were that easy to convince him to let people out of his realm, someone else would've probably done it already? But no one ever leaves the Underworld once they've gone in. I'm already doing something impossible just by going. Who am I to think I could do it twice?