How do you get two eevees in hearthome city?
well i went to the house left of the contest center and in there is a girl called Bebe (this was after i beat the Pokemon legue and finished my Sinnoh pokedex) I talked to her and she gave me a female eevee. I was really lucky that I got a female cause the time before i got a male after that i put the female one in the day care center and put it with a Pokemon that it doesn't like (you can check if it doesnt like it if you go out to the old man outside the day care and talk to him after giving the Pokemon to the day care) then i made it have LOTS OF BABY EEVEES!!!!
Edit: You'll just have to obtain an Eevee from Bebe, and then breed it with a Ditto or another compatible Pokémon if you want more of them.