(She’d labeled Rick an “A” in his trailer before setting him up to be mauled.)
And if that’s indeed true, then it means Lyla and possibly Leo sacrificed their colleague for the sake of research, which doesn’t bode well for outsiders like Rick and Heath.
The post-credits scene also possibly confirms a suspicion that some viewers formed from Jadis’ actions before the character’s exit: the “A” subjects are being purposefully turned into walkers for these research purposes.
There are obviously tons of empties out there in the world naturally, as it were, but many of them are rotted beyond usefulness, and without specific testing protocols involved, it would be mostly impossible to know how each and every zombie was turned, which wouldn’t be ideal for science.