Quote Originally Posted by John_Douglas View Post
Would this phrase be appropriate:

Я заметил ее употребление фразы "я скучаю тебя," дозволяющее предположить, что она плохо говорит по-русски.
Back-translating to English:

I noticed her use of the phrase "я скучаю тебя," which suggests that she speaks Russian poorly.

I think it might be better to say:

Её употребление этой фразы говорит о том, что она не хорошо владеет русским языком.
Her use of this phrase attests to the fact that she doesn't speak Russian well.

Instead of говорит о том, что you could also say подсказывает о том, что ("it hints at the fact, that...")

And there are various other ways to express "it suggests to me" or "it leads me to believe" or "it makes me think," etc. A native speaker can give you better advice about which one sounds best in this context.