I can only guess what the context here is but to imply that "they're fine with kids getting raped" is almost definitely an extremely dishonest strawman of what they're actually trying to say. This type of bad-faith dunking on people you disagree with only makes them dig down their heels even deeper and, I'd argue, is only making things worse.

If I had to steelman their position without knowing full context, I'm assuming that what they're trying to say is that abortion shouldn't be legal just because of the comparatively small number of cases where it perhaps would be justified (incest/rape) because it opens the door to a huge number of what they see as unecessary abortions.

If one truly cares about changing minds rather than scoring worthless internet points then you need to take down the foundations - not break the windows. Breaking windows is fun and easy but it doesn't achieve anything. Listen to what people are saying and challenge their core beliefs.