Commentary
And yes, "Cheerleadra" is a verb.
It's just SLIGHTLY possible Ellen has considered this before. Which is convenient, as gradually working through all these issues with just going ahead and saying "sure, come on over to Tedd's house" could have taken literal pages otherwise.
Aside from "magic secrecy goons" (hey, goons!), the biggest complication is explaining such a sudden transformation, and proving one is who they are. Unless, of course, they intend to only be transformed when they can do so in secret, which has its own set of complications.
Now, it is absolutely possible to nitpick some of what Ellen says. Elliot could potentially respond without having to confirm he's Cheerleadra, Tedd thinks he might know how to make permanent transformation wands, etc. The point is that there are complications, and reasons why it could all go wrong and wind up ending very badly.
As for the potential for it to be a trick, I don't think I've seen anyone consider that. As cynical a notion as that is, it's a possibility they have to consider (at least until one of them gets a "detect truth" spell).
