YOU SAID:

My sister is very mean.

INTO JAPANESE

私の妹はとても意地悪です。

BACK INTO ENGLISH

My sister is very nasty.

INTO JAPANESE

私の妹はとても厄介です。

BACK INTO ENGLISH

My sister is very annoying.

INTO JAPANESE

私の妹はとても迷惑です。

BACK INTO ENGLISH

My sister is very annoying.