Re: pronunciation, essentially we don't know, as we don't know if the OP's family are Japanese, because she hasn't come back to the thread.
If they are Japanese, then AFAIK they're pronounced e-tsu-ko & e-mi-ko with even stress placed on each syllable (e as in 'yet', ko as in 'cough').
If they're not, and they just like the names, then they can pronounce them any which way they like 