Yeah. Your point was spot on and I agree with it completely. Christian apologists can't help themselves. Any criticism of Christianity and they are all over themselves with either "Not all Christians", making sure you know the whitewashed version of Christian history, "we've evolved", or a doubling down on "biblical authority".
There is no doubt that slaves in America were forcefully converted. The fact that Christianity found it's way into Ethiopia naturally during the same time frame (roughly speaking) is irrelevant. Her second comment was in line with that though it was also a double down. Did you see that one? Part back stroke and part "but Ethiopians ARE Christian".
The fact of the matter is that most Christian peoples in antiquity were forcefully converted by the Rome Empire after Christianity was adopted by Rome. I'm a descendant of the Pict, who were forcefully converted. And the Cherokee, forcefully converted. And the Huns, forcefully converted. And the Celts, forcefully converted. And no telling what else. I probably do have African blood, again forceful conversion.
Many of those peoples were slaves or subjugates of Rome. One could argue that slavery seems to follow Christianity because Christianity is Authoritarian. Which makes their current authoritarian push troubling on a whole new level.