Given that the secular law allows abortion on demand, how much is the Church bound to respect it?
Right, but canon 1090 specifically mentions "crime" so it is important to ask, whose definition of a crime.
I ask this because I think the time is approaching when the Church will have to recognize no civil law and instead rely entirely on her own internal jurisprudence. That is because the secular law is departing from the natural law not just on one issue that one might call exceptional, but more and more presents a coherent in its own way secular outlook incompatible with Christianity in toto.