Regarding the current panic that Rosesprite and Jaspersprite have prototyped together, I would just like to point out that Jaspersprite has already been prototyped twice, and sprites cannot prototype with other sprites (seriously, why would the game ever allow something as mindfucky as that?).

The way I see it, sprites can touch whichever kid owns their kernel just fine, and will not EVER absorb them as long as the kid is alive (since dead bodies count as objects). It’d be pretty dumb if they could, from a game standpoint, since the players are supposed to get advice from the sprites and use it to play.

In the retcon’d timeline, Fefetasprite does not exist. Instead, Jaspersprite dug up the dead GAME OVER Rose and used her body to First-Tier prototype Roxy’s empty kernel. Rosesprite could now physically touch Roxy, who owns her kernel, but not Kanaya - were Rosesprite to ever touch anyone but Roxy, they’d be Second-Tier prototyped into the kernel.
Vriska is perfectly justified in her panic to stop people from touching Rosesprite or Tavrosprite.

Some things from canon to support this:

• John high-fived his kernelsprite before his nanna’s ashes ended up in it and did not get prototyped himself.
  
• Kanaya’s sprite touched her shoulder to comfort her.
• Jadesprite was created with an alternate, dead Jade (a corpse/her Dreamself).
  
• Davesprite was created with an alternate Dave from another timeline, and therefore the kernel did not recognize him as its designated kid.