Cheeky!
It's a total crapshoot, but if you have the free time during one of those "pummel before big hit" style Final Smashes, the trajectory of her neutral B, the almost non-existent knockback and the high fire-rate on the bullets makes her one of the best characters for blatant KO theft. Might as well try in that scenario, what have you got to lose?
Well, apart from your dignity. That was disgusting on my part. Would, and will, do it again.
Holding A after doing an air attack is another great method to do this. Forward Air is normally the most reliable attack.