YOU SAID:

My sister is on the toilet for an hour on average.

INTO JAPANESE

私の姉は平均1時間トイレにいます。

BACK INTO ENGLISH

My sister is in the bathroom for an hour on average.

INTO JAPANESE

私の妹は平均1時間浴室にいます。

BACK INTO ENGLISH

My sister is in the bathroom for an hour on average.