The claim that Jews can be saved only by accepting Jesus is a Christian doctrine. As a Jew, I obviously don't accept it, but there's nothing wrong with a Christian saying that.
What is wrong, and outrageous, is her claim that America would be better off if all Jews became Christians. That is not a religious belief, it is a secular claim, and one which is not only demonstarbly wrong, but is a slap in the face to all Jewish war veterans and to all the other jews who have done so much for America.
Well, the extension of that Christian doctrine which you say “there’s nothing wrong with” a Christian espousing is that ALL people would be better off if they became Christians. So, of course Ann would say that America would be better off if all Jews became Christians, just as it would be better if all Muslims, Hindus, atheists, Jehova’s Witnesses, Mormons, etc. became Christians as well.