YOU SAID:

My mom had three kids before having two and seven kids

INTO JAPANESE

私の母は2人と7人の子供を持つ前に3人の子供がいました

BACK INTO ENGLISH

My mother had three children before she had two and seven children.

INTO JAPANESE

母は2人と7人の子供を持つ前に3人の子供を持っていました。

BACK INTO ENGLISH

My mother had three children before she had two and seven children.