I thought it’s too early for you to learn English at the time because I thought that might prevent you from learning Japanese, but I decided to send you to an English school as a result.
I thought it’s too early for you to learn English at the time because I thought that might prevent you from learning Japanese, but I decided to send you to an English school as a result. 「英語を早く学ばせることが日本語学習の阻害要因となるかもしれないと考えたので、まだ早すぎると思っていましたが、結果として、あなたを英語の学校に行かせました。」
as a result の同義語として、consequentlyがあります。
ご参考になれば幸いです。
I was a little concerned if she started learning English too early, it might slow down her progress learning Japanese, but in the end I decided to expose her to English.
この場合、次のような言い方ができますよ。
ーI was a little concerned if she started learning English too early, it might slow down her progress learning Japanese, but in the end I decided to expose her to English.
「あまり早く英語を習い始めたら日本語の習得が遅くなるかもと心配したが、結局習わせることにした」
to slow down one's progress learning Japanese を使って「日本語の習得が遅れる」と言えます。
ご参考まで！
日本 
カナダ 
