And when everything is said and done, unless some third-party requires its use, encourage this client NOT to use BitLocker.
Full drive encryption is another of those things in the security world that is becoming grossly overused in situations where it's simply not needed. And the amount of heartache I've observed that results from people losing material because they blithely, and without due consideration, turned on BitLocker or other full drive or device encryption without a second thought, and then it went south somehow, is huge.
There are other options, like VeraCrypt (for one), that allow you to create encrypted containers for those things that really warrant that level of protection. For most home users, that would be a very tiny subset of what is on their machines, and it doesn't take much thought to decide what that would be (not much more than, "If this were on paper, would I be really upset if someone were to get their hands on it and could it be used to do something like steal my identity?").