Slang idioms

"It is so hard to do anything with Shannon. She is such a ...... She asks a million questions that are all doom-related. For example "Are you sure your tires are good? I don't want to crash. Are you sure we won't get bitten by a wild animal on the hike? Are you sure we won't get sick from the food at the restaurant?" I have given up on inviting her to events," Shelly told Cara.