Taking stock of the timeline:
Field assignment: The Sidershores, the thirteenth to the twentieth days of the month of Ascending Water, Realm Year Realm 770 (local reckoning)
...
You arrive days ahead of time, on a ship flying Cynis colours.
"She's been dead for well over a week, two at most." Next, she points at Cold Rain. "Maybe five days? And the man at least a day, but not much more — not as putrefied as the others, but the stiffness has passed. No bloating on any of them because they're carved open like that."
Okay, so Cherry killed Wood Sparrow before we arrived, Cold Rain right around the start of the gala, and Five Gardens (we think) when he propositioned a bit over a day ago. We met the real Cold Rain once, on camera (possibly more times that weren't narrated).
I note that when we investigated the sky mantis tower door, we caught sight of a guard uniform around the corner. I assumed that was Wood Sparrow, but it might very possibly have been Five Gardens, and his form may have given Cherry access she wanted to advance her plans.
Wood sparrow to was the one to talk of serving them most of her life when she is supposed to be young and the anathema's first victim on the island was a sentry, and Mama Cold Rain bothered to take gardens aside for a scolding about the way he was propositioning pearl, which does not seem like something bitter Cherry would make time for were Cold Rain her primary host.
They're all Cherry (unless some of them are in fact another Lunar accomplice). I don't know the ins and outs of how Lunar body-splitting magic interacts with their shapeshifting, but we can be very confident that she's taken all their forms. She can at least switch between them at her convenience. It's possible her duplicates can each shapeshift accordingly as well, or maybe she makes duplicates to wear the forms she's not currently using and then reabsorbs and swaps them around when she needs to. I don't think there's any issue of "primary" or other "hosts", there's just whichever face the "real" Cherry who has full access to her charms and powerset is currently wearing, and which faces are on less capable offshoots
for now.
Using the opportunity of a free guard behaving badly towards a slave girl to take him aside and eat his heart actually sounds completely consistent with how Cherry seems to think. It's plausibly a thing that would genuinely piss her off, and a good excuse to seize a valuable opportunity.
If I were to take a look through the papers that came on the ship that brought you, would I even find a proper bill of sale?" Maia asks, not relenting an inch.
...
"As if anyone would give a supposedly high-value slave as a wedding present to a matriarch's daughter without a paper trail to go with her. To brag about the expense of your training, if nothing else," Maia says.
This is why I voted for impeccable credentials, but no...
The irony being that it's Grace who must learn from L'nessa to shut up and let her servant work.
I think what Grace wants is for House to be a better student of how to communicate "shut up and let me work" gracefully. Look how well Pearl manages!
There was an agreement doing the last meeting we witnessed that their next meeting would see Sai explain what was going on, provided Amiti still remembered Sai at that time.
Yes. Specifically, Amiti notes that arcane fate just straight up isn't working on her - not only does she remember Sai when she sees her, but she remembers her in between and is able to talk about her to others (who have no idea who she's talking about). Although her soul wound may have healed enough in the meantime to lose this semi-immunity, it might not, in which case Amiti would know a
lot we don't expect.
Amiti looks around for a bookmark, one hand in between the pages of her book to mark her place in the meantime. "Everytime you show up, before I say hello, you have this look like you're trying to not get your hopes up. And everyone else who's met you or who I've told about you forgets and treats me like I'm making up nonsense, which is very vexing! I tried writing about it in a letter to my sister once. Her reply said it arrived half-burned."
...
"Tell you what — if you know who I am the next time we see each other, I'll tell you all kinds of things," Sai says.
Amiti is giving you a surprised, thoughtful look that seems to have knocked her out of her panic. Her gaze is lingering very intently on your eyes.
To me this reads as Amiti at least recognizing that Grace is the same sort of thing as Sai (who she may not remember clearly), and at most realizing that Grace is a Sidereal and knowing exactly what that means. (Which is going to be very, very funny if it turns out Amiti is the only one with object permanence for Grace while she's doffed her resplendent destiny. How many goes of Amiti having to explain this mysterious person no one else can remember to Maia, Ambraea, et al before they come to the obvious conclusion: Grace is some kind of ghost?)
...Actually, double checking, there is a scene the year after Grace exalted where Maia asks about Ambraea's new handmaiden and is puzzled that she half-remembers the old one but neither of them go anywhere with it. Amiti is present, but doesn't comment. So it's even possible Amiti does remember Grace - to the extent she ever knew who Peony was, which is probably barely at all.
As to the vote...
[x] "Five Gardens", a humble footman
[x] "Wood Sparrow", a sentry
I think Wood Sparrow would be a neat bookend on Cherry's first victim, but Five Gardens might be the most acutely relevant to what seems to be the main thrust of her plan here.