OK so here's what I got. Alice the princess was super depressed after MC died. So she wouldn't eat and was ready to kill herself. Then her father thought about the last words that MC said "see you guys later". And figured that that probably meant MC was going to be reborn. So she got out of bed, ate a lot of food, and dedicate herself to learning magic and studying the sword so she could be reborn with MC. Eventually, she figured out how to do it, and Little bit after her little sister was born she stabbed herself with a sword and was reborn in the same era as MC. While her mom and dad dedicated themselves to eradicating that church from the planet.

Let me know if i missed anything.