This isn't an ordinary well; she knew that just a moment too late. She doesn't know if something was just inherently different, or if Mr. Eaten set a trap for her, but either way, the result is the same; she has fallen farther than it usually takes her to get to the bottom--
Something changes, and there is light.
She has just a moment to look up and see stars before she lands in the mud with a craterous splat.
She pulls herself up and onto something at least approximating dry land. The mud slides off her dress with no assistance, but she has to mutter Correspondence under her breath while finger-combing her hair before it appears spotless again.