my first reaction was that she was a program. (which i am still 85% sure of) but she said that she could once feel love but could no longer. maybe she was a person and then got trapped inside beacuzse the matrix needed someone to explore human emotions. but the oracle said that the merovingian is a program so probably his wife is too.
neo would know if she was just a human who says she's a program. he's got the magic perspective.
and in either case, she's a program-thingy. not human. i read that before m2 came out -- that she was just like the merovingian, that she was kind of a vampire, and that she was able to tell when people were lying ("she wasn't kissing your face"😉.
Persephone was most likely a program with a purpose once. She may even be “the child” whose protection caused the Oracle to loose her old shell.
When a program loose its original purpose it changes. Just like our friend Smith tells Neo in M2, that his drive for purpose made him stay, although the purpose has changed from system-agent to destroy everything.
So Persephone was a program send to investigate human emotions (probably). Then her and the Merovingian were done as programs, but chose to stay. In Etm she tells Ghost, that once she didn’t even know what it meant to wonder what one wanted (purpose). Now it’s all she ever thinks about. That would make her a program.