Will someone please share the other procedures that could have been done?
Depends on the condition involved. In many cases either something can be done to attempt to save both or to mitigate the risks.
After some looking in this case she had Pulmonary Hypertension a potentially fatal condition somewhere between 30-50%. In this case some things can be tried. One is a epoprostenol infusion. This is a fairly new procedure that has shown great promise and success.
Early recognition of PPH drops the mortality rate from 50% to 30%. The epoprostenol therapy before, during and after a C-section drops it further.
For a good overview of the condition plus multiple article sources on it see:
Here
The issue is that often doctors will recommend termination before other options are attempted. So in addition we have the previously mentioned fact that the child was treated as the disease and the intent was not to help both but to kill one. Also the Sister attempted to justify the abortion as fitting with the Principle of Double effect and Catholic Dogma. That was not true since evil can never be done as the intent in order to do good.
We would view this the same as someone saying...you have a 30% change of dying but you can live if you kill the person next to you. There is no difference in dignity or rights between the fetus or the grown adult.
Zygote, Fetus, infant, toddler, child, teenager, young adult, adult, middle aged or senior citizen...they are all equal as people. From the moment of conception there is a human nature present. A human does not start as something else and become human that is not the way science or theology works. Once conceived all that changes are physical characteristics such as biological development not the nature of the being as human and all the rights given by God.
That is why to a Catholic and as proclaimed in unchangeable teaching by the Church (earliest recorded in 100 AD and confirmed as definitive Magisterial teaching by JPII) it would be the same to perform an abortion to save a life as it would be to shoot the person next to you to save a life.