LOL, 5 blankets? doesn't sound like a self soother to me. Funny how the parents definition is always a little different then ours.
I have one blanket boy. He needs it all day every day. When he was transitioning I would allow it, but not at the table and not outside. Now that he's comfortable we're working on putting it in our bag when we get here and getting it for nap then putting it away after nap, just like the other kids do with their soothers. He always gets it out when mom comes, but that's moms problem at that point.
Crying for an hour before sleep for 2 weeks is nothing! I've had them cry for a full 30 days through their entire nap. She'll get it once she's more comfortable. Give it time and let her cry it out, she'll get it. And as for the blanky, I'd let her have one, but not 5. That sounds like it's more for the parent then the child. Then I'd start weaning her down to only at nap time. Let the parents know what you're doing as it's a safety hazard for her and the other kids and they need to do the same at home. It's ok to have something for security, but dragging a blanket around is just dangerous... and a germ cather!
Are they 5 specific blankets? So strange. I've never heard of such a thing!