@A Lowly Wretch Yeah, that is true considering Sophia's character. If Noriko headed off, Fuyuko probably wouldn't be able to find Sophia again, so that could make things difficult.
Of course, it depends what you want to do. If you'd rather have them continue talking, yep I'm good with that, Noriko will probably leave soon anyway as it's getting darker and shades will be more active, she needs to keep her home safe. Plus I kind of want to focus on my actual participant character. If you want Sophia to be alone for a while so she can do some observing, we can do a shade fight, then I could have Fuyuko meet another group of magical girls or Vita could throw an NPC at her. I'm happy with whichever option you choose :)