Yeah, not giving an answer right away is the best call here. The first thing I'd need to know is what happened to the father. If he's dead, that's probably the safest sign she's alright. Anything else has its own set of red flags.
Consider how convoluted the writing has been in this series so far. I propose that Natsuki isn't secretly disguised as the maid. Instead, "Natsuki" was the maid and the father planted her in the class to teach his son a lesson. And this whole story is probably a crazy scheme to push his son into...
Like, I understand if she was attached to the dragon and wanted revenge, but she ain't. This chick gonna get her whole organization clapped for no reason.