just to clarify because i think you sort of said you were wrong but i'm not entirely sure...
if i read 17 U.S. Code ยง 201 (d) clearly, it suggests you can transfer ownership of copyright in any normal legal way of executing a contract.
I think your confusion is around the idea of works falling into the public domain via expiry of copyright, and/or works that do not have an explicit declaration of rights ownership.
In this case it seems she was pretty clear about her transfer of ownership. I don't believe you can rescind that just as you prefer, at any time.
if i read 17 U.S. Code ยง 201 (d) clearly, it suggests you can transfer ownership of copyright in any normal legal way of executing a contract.
I think your confusion is around the idea of works falling into the public domain via expiry of copyright, and/or works that do not have an explicit declaration of rights ownership.
In this case it seems she was pretty clear about her transfer of ownership. I don't believe you can rescind that just as you prefer, at any time.
see https://www.law.cornell.edu/uscode/text/17/201