"There is nothing to protect or give rights to"

1. We protect inanimate objects. Are you asserting that fetuses don’t even exist?
2. There is nothing “scientific” or empirically derived about an application of moral valuation. This is simply you confusing yourself over word salad.
3. “It’s only complicated because of different spiritual beliefs”- And yet the poster gave a non-spiritual reason. So why didn’t you show that it’s either not complicated or that the user is actually relying on spiritual beliefs?

“Clearly should have a right to her own body”

This is actually not clear at all. Consider self-harm, if people actually do have a right to their own body to do whatever they please then we have absolutely no right to take any measures to prevent self-harm; it is a violation of their rights. So if someone says “I want to cut my arm off”, you have no basis for saying “no you really shouldn’t” because it is “their body their choice”. The minute you say “Actually self-harm is irrational” means that it is not what the person wants that matters, but what a rational person would want. And then one could easily argue that a rational person wouldn’t want to engage in self-mutilation or killing a fetus. This is known in the literature as the “suicidal Bob problem” or the “argument of the idealised self”.

This and many other issues with defining bodily autonomy in such a way as to permit abortion is why it has largely been rejected in serious ethics; it’s only popular among the public because it’s essentially an elaborate appeal to emotion fallacy.