I'm sad that they couldn't extend her life even further, but I'm glad he gave her what he could. And in the end he made a difference in her life and she made one in his.
I swear officer, one is my adult professor and the other is my imouto! There's nothing wrong going on here.
On the other hand, why bother with mirrors when he can probably use his magic to create a hole in space to see his own back?