Putting my own veiws on this aside(which are that abortion is not for me and I personally do not think it is a good thing - although i would NEVER push that veiw on someone else - it is a personal choice you need to make. It is not my place to say whether it is right or wrong for someone else.)

There are a number of variables that would make me feel it right or wrong.

IF the woman did it HERSELF - that is ABSOLUTELY wrong in my eyes. Simply because although she is a nurse, something could have gone wrong and the cat could develop complications either during or after, not to mention im sure the nurse did not have adequate pain medications on hand to prevent the cat from suffering - and im sure she didn't have anasthesia on hand to put it under.

IF a vet did it - that would be kinder i think as the vet could put the cat to sleep and then do it under general anasthesia so it did not suffer, and could make sure the cat didnt hurt when she woke up and didnt develop an infection or complication afterward.

Also you say the cat was VERY pregnant.. and i think that disturbs me. I know they often do abortions in cats that come in to be fixed and are only slightly pregnant(up to a certain point) but i would think it would be traumatic for the cat, not to mention dangerous, to do it after a certain point.