To clarify, Catholic faith does NOT demand the option this mother is bravely choosing. The doctors are denying her treatment, which is unethical.
Of course, her Catholic Faith absolutely prohibits abortion.
But if the doctors are denying her treatment because she won’t kill her baby (which seems to be the case) then they are killers.
This mother sounds like the kind who would refuse the treatment of it endangered her baby, even though such treatment would be morally licit.