Technically, what she wants is a cenotaph, not a grave, but..
Thinking about that...I might forget my friend too someday.
I don't like it.
In other words, what she's making is a grave for her own sake.So she herself won't forget...That's what the grave is for.It might be missing the point of a funeral, but...There's nothing fake about her feelings for her friend....I see.