"You will have time." Referring to both Mercury's current incarnation, and the eternal existence she would have. "Because of it... I hope you fix this all. And that you get the life you want."

She would have a better chance at making the life that she wants by time alone. If not in her current life, then in the next, either as a doctor or as a queen, instead of being divided between between the girl and the soldier.

In his case, he has already accepted he would have only one of those lives.