Is there really any moral dilemma here?

NPR carried the story of a 27-year old woman who arrived at a Catholic hospital, 11 weeks into her fifth pregnancy and seriously ill. The doctors told the woman that if she continued with her pregnancy she would almost certainly die. She was too ill to transfer to another hospital.

So the woman had the pregnancy terminated, after the nun in charge, Sister Margaret McBride, permitted the procedure, thinking that Directive 47 applied -- "Directive 47 in the U.S. Catholic Church's ethical guidelines for health care providers — that allows, in some circumstance, procedures that could kill the fetus to save the mother." The woman survived.

The Bishop of the diocese, however, promptly excommunicated the Sister.

There is some controversy because the Church never acted so promptly and harshly in the case of (male) priests molesting little children. Leave that aside, let's look at the moral reasoning.

The Bishop's reasoning is ""There are some situations where the mother may in fact die along with her child. But — and this is the Catholic perspective — you can't do evil to bring about good. The end does not justify the means."

According to a professor of theology, "The official church position would mandate that the correct solution would be to let both the mother and the child."

From my perspective, the choices are
a. Do nothing - both mother and fetus die; four children are left motherless.
b. Perform an abortion, mother survives.

The first evil is in doing nothing and letting a tragedy grow bigger than it need be. By doing nothing, you are killing the fetus anyway, so that is your baseline of necessary evil in this situation.

The second evil is in punishing someone for choosing b. If I can't save two, shouldn't I at least try to save one.

Since I don't understand, I guess it is a good thing I'm not a Catholic.

PS: If both mother and child died, and one death was unnecessary, would the Church defend against a claim of medical negligence?