No, our choices are not meaningless. I will end up creating an essay from your question, but I attempt to answer briefly here. The soul of the baby elected to play a role that has it dying no matter what the mother chooses, but her choice has much meaning for her and her soul. Meaning is not necessarily found in outcome but in intent. The concept of karma has been mangled in the west to mean cause and effect and what goes around comes around but it has very little if anything to do with that. Karma is all about intent.

Free will very much exists. It is not an illusion. There are only two aspects of everyone's soul contracts that every contract shares, entry date and exit date, which I also use to discuss suicide attempt prevention. https://medium.com/p/ac4c0c999e81 Certain contracts have other occurrences set in stone but for the most part soul contracts are much more like improvisational scripts than fully predestined life plans. How we live and how we die is very much the product of each of our free will and the chaos of the interplay with the free will of others. You can read my work on that here https://medium.com/illumination-curated/life-is-school-for-the-soul-9b081dbe8453 and I always recommend the work of Jodie Helm, particularly this piece on this point. https://medium.com/@jodieshelm/archangels-q-a-6-b17b212773b5