I’m an adoptive father, and so I ask for people to not ask me to be unbiased on the abortion issue. That said- I can see a libertarian argument that you can’t force a woman to carry another life in her body, even if she helped make it.
I believe that the idea that something “happens” through a natural delivery, that bestows rights on a baby they previously were denied is a modern update to the medieval concept of “quickening” and is irrational.
I see a libertarian argument that when a woman decides she doesn’t want to have another life in her, but that baby is capable of surviving on its own (with the help given to newborn babies, of course; none of them are texting Uber Eats), then the baby should be removed in a manner that doesn’t kill it.