She has provided five witness statements

She has provided five witness statements to the court in total. These statements detail acts of physical, mental violence etc.

Yes, that is grammatically correct and has the proper meaning.

Another possibility is:

She has provided five witness statements to the court in total. These detail acts of physical, mental violence etc.

The reason that the above version is unambiguous is that there is only one plural noun in the previous sentence and so "these" can only refer to "statements".