I thought I'd better do some research, if I'm to play such a character... I found The Eyes of Tammy Faye, the website of a documentary that was made about this doyenne of the small-town girl goes large, falls, then gets back up again thanks to outrageous mascara use and the Bible story.
Such inspirational gems and tips:
"The only difference between the word bitter and better is the 'I' in bitter."
"I think the whole world should wear make-up."
"Hallucinations are really interesting, they're something I never had before, and I saw cartoons."