We sometimes have the student take a practice test according to the official timing regime, under conditions that simulate the real test. We can do this for the SAT, the ACT, and an SAT/ACT combo that is intended to let us compare how the student does based on the different character of the two tests.
Doing this with a paper and pencil test just like the actual test your student will take provides a more accurate assessment than oft-used online practice tests – that there can be a difference in results is well-known within the testing community. And paper and pencil is also exactly what your student needs to get used to handling.