I liked Willie and although ROTLA is the best, I have a soft spot for TOD. It was the first one I saw and the one I've seen most often. I don't deny that Willie's constant shrieking and screaming is annoying as hell, but she's an ordinary woman who was living a very sheltered and pampered life, abruptly thrust into what is frequently a utterly terrifying situation. It's completely understandable.
All things considered, she holds up pretty well--she sincerely tries to get help when Shorty and Indy are kidnapped (in a deleted scene), she jumps right in to help free the slave children, and she practically becomes a Mama Bear to Short Round despite initially being annoyed by him. I particularly that bit when she smirks at Nola Ram when Indy threatens to throw away the stones. Despite all her carrying on, she fully understands their importance.