Board Thread:General Discussion/@comment-26006155-20190617222636/@comment-26006155-20190707222256

Also, Toriel tells Frisk that she knows exactly what happened to the other Six Humans before him (although she never actually gives a number).

Toriel, with her cell phone, and its upgraded texting ability, still has contacts in the Underground, and knowledge of what is happening there. She's not completely isolated.