Well, if the person in case is minor I dont see the problem of doing it as your the responsible but in the other hand, choose to teach someone how to install a spyware on a device is like teaching how to pick through a lock and who knows if this lock is yours or not.
You can be sure none here mean to be unhelpful, its completely the way around, we are preserving not only you but other ppl that may find this forum to get this knowledge and abuse of it.
All in the name of a clean forum. Im sure this info can be found on google tho, just have to look harder.
I hope everything will turn out good for you.