- Introduction of the summoned maid

- Voltaire's maids

- Voltaire's maids again (earlier in this arc, simply behind Voltaire)

- Hope promising to tell Tedd about her summoned maid

- Voltaire's maids yet again (still simply behind Voltaire)

- Hope shows everyone her summoned maid

- Three pages later, three maids of Voltaire's

And, of course: Ragnarok.

Worth noting:

• The maids act autonomously once summoned, but have guidelines for behavior.
  
  
• The maids are not morally, well, anything, but they're designed to "simulate moral good."
  
  
• The maids HAVE to be summoned from within an immortals room.

That last part doesn't guarantee much of anything specific, but it does limit possible explanations regarding when / where these three were summoned, and where they could've been just before now.

Which is an interesting thing to consider, really. Many bits of information are much more useful for removing possible answers than outright answering them.