Nope!

And a small Cordelia presumably goes fine?

Yup!

"Okay I can do small people to check."

"So then I want to check a bunch of people from different planets and find out who's magic and who isn't - when we only knew Nika I thought probably it was either something from Earth because we found out she's from Earth or it was something from Barrayar that got her when she came here, so I wanted to check a bunch of people from Barrayar and a bunch of people not from Barrayar because if it started on Earth and it's all over Barrayar then we know it started before the Time of Isolation and if it started on Barrayar then it'd be all over Barrayar but not all over the rest of the galaxy," says Miles in a rush.

"Very scientifically rigorous of you," says Cordelia approvingly. Miles beams.

"Oh and you're here now so we can figure out more things about where Nika came from! Let's do that!"

"I need something to specify people - doesn't have to be names but more than 'a bunch of people from Barrayar' -"

"I was recently reading census data, actually, I can name a few local towns whose population I know precisely - if I said 'Rosedale, population fifty-eight' could you try to conjure them all without having to specify them to the level of the individual?"

"Yeah - 'the whole population of Rosedale' works, don't even need numbers, though they'll help with figuring out what percentage of people are magic -"

"Yes, that's what I was thinking - it wouldn't be much use if I named a village and you conjured a hundred people and we didn't know whether that was all of them or half or ninety-eight percent. Well, what happens when you try to conjure miniature versions of the whole population of Rosedale?"

He tries it.

The whole population of Rosedale is apparently magic.

"Uh, all magic."

"...Greywood, two hundred and five..."

He tries that one.

No small people appear.

"...Can you stop in the middle if they start piling up outrageously? If so, Salair, three hundred thousand—"

Everyone from Salair is also magic.

"This might be a magic planet."

"Running with that hypothesis, if you try to conjure the entire population of Vorbarr Sultana, capital of Barrayar, we will end up with a small pile of ambassadors and diplomatic staff and possibly a handful of immigrants. Let's find out."

He tries it.

A small pile of models. Cordelia examines them. "Ambassador, diplomatic staff, not sure, another ambassador... I would say that about ninety percent of these people are definitely not from Barrayar, and the rest are at minimum plausibly not."

"But Nika's not from Barrayar and she's magic," Miles points out.

"Yes, and that's interesting too... can you verify that Nika was magic before she arrived on this planet?"

He tries to make a small Nika the minute she was born.

She was a magic baby.

"Hmm. Are Nika's biological parents magic?"

He tries that.

Yup! Or nonexistent, can't technically rule that out.

"Magic." And he shows her the models he made of where Nika was born - "don't know what that thing is -"