[X] Offer your condolences. Tsuchiya Ritsuko is almost certainly dead, or she would be famous by now for living so long.
-[X] As far as we know, Hitomi is not a potential. The only reason we've involved her at all has been to prevent exactly what was just described.
[X] Mami has homework, ask if Mrs. Shizuki is opposed to the content of the conversation so far being "public" so Mami has a response to "what was that about?" You'd like to give Mrs. Shizuki the broad strokes of the current situation, go over w. Mami what you're expecting to talk about -- none of it is anything she's unaware of.
[X] Explain briefly: the masquerade, soul gems (lichbomb + need for grief seeds), Walpurgisnacht, your powers, the expected influx of meguca.
-[X] Disaster insurance might not be a bad idea.
Uh, first, moratorium is active.
Second... Wut?
That's what you want to open with?
Likely, but not guaranteed. We could ask Nadia via telepathy
I was thinking just about that.
Votecrafting... This is a mess.
[ ] Thank Mrs. Shizuki for sharing this with you. You actually wanted to talk with her, and other adults about this.
-[ ] Urgently telepathy Nadia asking if she knows about Tsuchiya Ritsuko.
[ ] Reassure Mrs. Shizuki that Hitomi is not a Potential and won't become a Magical Girl, nor will she need to fight Witches
nor will she lose any friends to Witches, if we can help it.
-[ ] On that note, explain the fact of Magical Girl's lives, and how you're trying to change them for the better.
-[ ] And how you need help to do it. Possibly mention Hitomi's 'friends' who are to arrive tomorrow.
[ ] Once you get an answer from Nadia, warn Mrs. Shizuki if appropriate, and share the facts about how long Magical Girls usually live, and Tsuchiya Ritsuko's fate, if Nadia does know of her.
-[ ] If Mrs. Shizuki isn't doing well, offer to continue the conversation later.