"She is taking a shower now."

Translation: 她现在在洗澡。

[TreeTempo]

她正在洗澡？

[KX3.]

This is fine, but take note that 正在 carries the meaning of "she is (doing this) right now".

[kuyaC]

Is 洗澡 like 跑步, first character a verb and second character a noun?

[jamesjiao]

Yes, you can think of it this way. Normally verbs like this are intransitive.

[BrettNoChinese]

Should 她现在洗澡 be accepted or is the second 在 required?

[KX3.]

It is required.

[Wyatt961236]

It is not required. If they wanted the English to reflect the necessity of the second 在 they should have said, "she's in the shower right now"

[duckmaestro]

What is the grammatical reason for this?