Turbotax Desktop for a family member in another state

I want to download Turbotax Deluxe Desktop for myself and my son.  But I live in NY and my son is in college in CA.  With my 5 efile account, can I download to my computer in NY and then can he download to his computer in CA so I can FaceTime with him and take him through the process (he is a first time filer)?  Or can the software only be downloaded once and then used to efile 5 times from one computer? His laptop doesn't have a CD player so I can buy the software on a CD then mail it to him after I put it on my computer.  Thanks.