I suggest you learn the difference between a dangling participle and a misplaced modifer. A participle is usually in the for "...ing" and represents an action, the ongoing or abstract sense of a verb.

The couplet

So one day at dawn, with her nightdress on
He cut her bloody throat.

does not contain a participle, dangling or otherwise, since the only verb is in the past tense. It could be argued that "with her nightdress on" is cognitively identical to "wearing her nightdress", but in grammar it is the form that defines things. One does wonder how her throat got bloody before he cut it, as implied by the second line, but that is just more bad writing. Not grammar, and probably not truth.

A