I gave my little sister a ride to a train station where she could catch a train the rest of the way home.
この場合、次のように言うのはどうでしょうか？
ーI gave my little sister a ride to a train station where she could catch a train the rest of the way home, so she wouldn't have to change trains.
「家までの残りの道のりを乗り換えなしで帰れるよう、妹を駅まで車で送ってあげた」
to give someone a ride to a train station で「人を駅まで車で送る・乗せてあげる」
to catch a train で「電車に乗る・間に合う」
rest of the way home で「家までの残りの道のり・道中」
to change trains で「電車を乗り換える」
ご参考まで！
I drove my sister to a station partway and dropped her off there.
I drove my sister to a station partway and dropped her off there.
I gave my sister a ride to the transfer station so she wouldn’t have to change trains.
I drove my sister as far as the (name) Station and dropped her off there.
英語では partway / part of the way / halfway / as far as ～ をよく使います。
* partway / part of the way
「途中まで」という意味をそのまま作れます。
I drove her partway.（途中まで車で送った）
I drove her part of the way.（途中まで車で送った）
このあとに “to a station” を足すと、途中の駅まで、がはっきりします。
カナダ 
アメリカ合衆国 
