YOU SAID:

my mothers older sister was born yesterday on my upcoming birthday

INTO JAPANESE

私の母の姉は昨日私の次の誕生日に生まれました

BACK INTO ENGLISH

My mother's sister was born yesterday on my next birthday.

INTO JAPANESE

昨日、私の次の誕生日に母の妹が生まれました。

BACK INTO ENGLISH

Yesterday, on my next birthday, my mother's sister was born.

INTO JAPANESE

昨日、次の誕生日に母の妹が生まれました。

BACK INTO ENGLISH

Yesterday, my mother's younger sister was born on her next birthday.

INTO JAPANESE

昨日、母の妹が次の誕生日に生まれました。

BACK INTO ENGLISH

Yesterday, my mother's sister was born on her next birthday.

INTO JAPANESE

昨日、母の妹が次の誕生日に生まれました。

BACK INTO ENGLISH

Yesterday, my mother's sister was born on her next birthday.