YOU SAID:
She looked into the mirror and saw another person
INTO JAPANESE
彼女は鏡をのぞき、別の人を見ました
BACK INTO ENGLISH
She looked in the mirror and saw another person
INTO JAPANESE
彼女は鏡を見て別の人を見ました
BACK INTO ENGLISH
She looked in the mirror and saw another person
That didn't even make that much sense in English.