Sorry, don't really know! Young snakes do often make dumb and even bizarre feeding errors, like mistaking your hand for their mouse. But if she didn't bite you, then it probably wasn't constriction.
So I'm going to assume it was some kind of stress response triggered by something in her environment. Give her a week off, resume handling as normal? If she's still eating, she's probably fine?
(young snakes are also more easy to stress out. I've had a couple of new snakes COMPLETELY FREAK OUT when I put them in their new homes after shipping: Shaking their tails, rolling over, balling, snapping at everything. Adults almost never do that. But then again, I've never seen a young snake do it after they've had a month to acclimate.)
Definiltely let us know if she does it again! (or better yet, if she does it again, see if somebody can catch it on video with their cell phone.)