To be honest I didn't know she was part of the Heinz products family when her husband first started campaigning. I've never heard anyone put ketchup at the end of her name. I do think it's a little odd but then I do odd things myself.
As far as whether she did or didn't legally change her name I don't know why people make an issue of this. I've been reading Clinton's book and it was an when he was running for Governor. Hilary did change her name after they'd been married a number of years just to get people off their backs.