I don't believe a legitimate female DW Eevee is available. You get a male one in Castelia City for beating the game (B2/W2), but I haven't heard of it being female. I may experiment with this once I beat the game, however.
Keep searching, however. You might get lucky. Just make sure it's legit. before trading.
Keep searching, however. You might get lucky. Just make sure it's legit. before trading.