You can always ship it to the Internet Archive if she doesn't and you can't find a way to maintain an independent copy. Maybe by then you can set up some kind of organization like IA for the replication value.
That's a fair point, the idea is also to preserve the media that we as a family consume. Growing up my dad would take me to the video store and find old classics from his childhood, the archive contains many of those as well as all of the stuff important to me. I hope that she will add her own media and then pass it to her children (should she choose to have them that is). What we choose to read, listen to and watch tells us so much about who we are as a culture and as a people.