Medea, as portrayed by Euripides and other ancient authors, was not intended as a positive role model in any manner whatsoever, nor is she an example of female empowerment. If anything, she is precisely the reverse. Before the opening of the play, she sacrificed her brother and chopped up his corpse to delay her father in his pursuit of Jason. Murdering a brother and desecrating his corpse due to infatuation with a handsome foreign man is not the act of an empowered woman, but of a woman who defines her self worth in terms of romantic relationships, and has little in the way of an independence or ethics.
While she is quite legitimately angry at Jason for abandoning her, she does not kill Jason, but instead uses a poison to murder Jason's new wife, Glauce, an innocent young girl who is simply obeying the orders of her father. Medea's killing her own babies to hurt Jason, again, is not evidence of empowerment or independence, but of obsession with Jason. Rather than being a model of a strong independent woman, Medea seems rather unhealthily dependent on her relationship with Jason for her emotional state.