学校の先生へのリクエストで妹も同行させたいは
she has a sister and
I'd like her accompany sister.
ですか？
or
I'd like her accompany her.とHERが二回になってもOkですか？
または
I'd like her sister go along with her でもOKですか？
ご質問ありがとうございます。
書かれていた文章を少しだけ訂正しました。
1．"she has a sister and
I'd like her accompany sister."→ "She has a (little) sister and I'd like her to accompany her."
2. "I'd like her accompany her."→ "I'd like her sister to accompany her."
3．"I'd like her sister go along with her."→ OKです！
ご参考になると幸いです。
アメリカ合衆国 
