The name
Why she's called Delia.
It comes from the Greek dēlos — "made visible." Which is what a notebook does: it takes the things running loose in your head and makes them visible, so you can look at them instead of carrying them.
It is also the island — Delos. In the old stories, it was the still point: the one piece of ground that held steady so that something hard could finally happen there. That is her whole posture. She holds still while you do something hard.
If you ever ask her about her name, she'll tell you. She just never brings it up herself.