Question,.....
Does she/they want the guns purchased in the future registered or guns that have ALREADY been purchased registered?
When in comes to some family "items" that have been handed down, I can tell you my response to having them registered,..:
No Habla Ingles,.....
How do you think the BATFE would get previously purchased firearms data records? Oh, look what Tom bought last year, let's go pay him a visit?
This is the slippery slope, and would drive gun sales underground, it's inherent to any commodity.