I know it's a misquote, but does it really matter? Even if they were her views what she said then is immaterial to what the organization is now. It's no different then making claims about how it was the Republicans who freed the slaves.
It's an even more poignant point to be made when you consider that most of the arguments for gun control are specifically pointed at undermining the validity of the second amendment by saying when it was crafted it was impossible to understand and take into account the needs of modern society and the weapons we have access to. We can't have it both ways, we are either all tied to the lode stone of the past or we are all free of it. Anything else is hypocrisy, regardless of the cause, for better or worse.