YOU SAID:
While this oldest son could stay at home, all daughters were essentially expected to leave the house and marry the head of another family line.
INTO JAPANESE
この長男は家にいることができましたが、娘全員が家を出て別の家系の長と結婚することが基本的に期待されていました。
BACK INTO ENGLISH
The eldest son was able to stay at home, but it was basically expected that all the daughters would leave the house to marry another family head.
INTO JAPANESE
長男は家にいることができたが、娘全員が別の家族の長と結婚するために家を出ることが基本的に予想された。
BACK INTO ENGLISH
The eldest son was able to stay at home, but it was basically expected that all the daughters would leave the house to marry another family head.
That didn't even make that much sense in English.