I don't suppose she's more of a racist than other people. She said a silly thing, which she regrets. No one lives a life without error.
How many thousands of other things has she said and done that are not of this type? This is who she is also. Do we judge people on a single bad moment or on the pattern of their life? I think it is sweeter to do the latter.
I don't know much about her, but if she was habitually rude about people's race, I imagine it would be widely known.