Someone posted this on DS - a video compilation of Becky being "fun" to campaign for the wild card spot. Listen to her voice through the whole thing - the overblown accent is gone, the shriek is gone, it's actually almost pleasant on the ear (something I never thought I'd say about anything that Becky would utter).
There are occasional moments where she's legitimately performing, and then the obnoxious, exaggerated voice comes back, but most of the time it's not there.
I cannot imagine keeping that up for so many weeks. Could you?