I'm reading a Japanese manga and I found this "maybe" slang sentence. A female character is asked to perform as actress in a school movie and her answer is:
My guess is "An actress? I've never done it" but the grammar meaning looks obscure. Maybe I'm wrong but two negations arise: "ない" and "しなー." I think it's a contraction coming from "しない" or "しなかった". Probably some particles have been omitted too.