If a princess at an empress' residence, who is of a higher rank than you asks a favour of you, but you don't comply, even if it's a small favour, you will get punished.
この場合、次のような言い方ができます。
ーIf a princess at an empress' residence, who is of a higher rank than you asks a favour of you, but you don't comply, even if it's a small favour, you will get punished.
「自分より位の高い後宮の妃に頼み事をされそれに応じなかったら、それが些細な頼みであっても罰せられる」
日本語だと「頼み事をされる」ですが、受け身にすると不自然なので、to ask a favour of you のように言うのが良いでしょう。
ご参考まで!