First, I'd suggest reading the Herald American article linked in the OP. Hamill emphatically does not call "Jingle Bells" a racist song or ask that it not be sung. She does trace the history of its blackface performance from the antebellum south through the 1930s. It turns out the stink is not being made by Hamill, but by Breitbart, the Daily Mail, and the like.

Second, I'd like to ask you to put yourself in the place of an African American who is curious about the origins of a beloved holiday song, and in her research discovers that it was originally and then persistently performed in blackface--a form of performance designed to ridicule her race, appearing when Africans were thought subhuman, and used to perpetuate this belief long after slavery. Kind of spoils the fun, doesn't it?

I don't know how Hamill reacted, but if I were her, I'd think, "Oh, crap, they did it again. Is there no place free from this shit?"

As a white American, I think such reminders of the pervasiveness of racism in our cultural history are salutory and always timely.