each empty snake-like body floats

She never dreams of Petra.

It's because her dreams are full of other, less forthright things, but it's also because she doesn't have any expectations with Petra. Petra has all her own answers, to be provided year over year, and Petra will provide the metric of judgement, too. Not God, watching. Simply Petra's satisfaction.

Never "so many promises, and then it's paid - for now, for good, for bad, for ever." Not with Petra.

No fear of loss, whether power or communication. Not with Petra.

And so it never occurs to her, to think of all these girlish ghosts, with Petra.