I would have had an older brother, but he was stillborn. I never shared any of my toys with him, even though he didn’t have any. I had my own bedroom, and he didn’t, but he never complained about such mistreatment. And nobody in the family accused me of being selfish for thinking I was more important than him.
On the other hand, I didn’t even exist when he was born, so if my parents had not shared the information about his ill-fated arrival with me, I’d have never known he existed. Clearly he was still on their minds. They had made him, then waited 9 months for him to arrive. They had purchased a layette and picked a name. Of course, it’s a very different set of circumstances when a pregnancy is unwanted and is aborted early term. So the answer is it depends.
As to the law and where the remains usually go, I am neither a lawyer nor an undertaker. I’ll have to leave that part of the question for those Jellies who are knowledgeable in those areas.