Trying to say "her eyebrows furrowed" but cannot find the right expression. I recall there being a similar expression (which warranted a different English translation), but can't remember what it was...
The closest expression is probably:
Passive voice seems not to be very common though, unlike in English.
To add to the other answers, way back in some early 20th century novel (I don't remember exactly which one) I saw another expression. So if you want to go a bit more indirect and literary you could say
眉 (まゆ) を八の字にして眉間 (みけん) にしわを寄せる。顔をしかめる。「―・せて考え込む」 (source)
This is meant figuratively that you arrange your brows in a way that looks like the sign for eight (八). If you want to make the opposite you could also say
If somebody could clear me up whether its ぎゃくはち or さかはち, I'd be grateful.
Edit: As pointed out in the comments, the 逆 is in relation to 八の字 as a complete expression and thus read as ぎゃく and not as さか.
As is stated in the answer to this question here. I presume the answering person is a native speaker, but I personally have never seen that expression in novels.