I had a coworker/friend once that did the same thing. Because she knew how I felt about the procedure she did not tell me until it was over. You have to look at each situation. In her case, she had two choices 1) give the cats up or 2) have them declawed. I think she made the right decision and today all 3 cats are happy and healthy.

Personally, I'm totally against declawing and do agree that it's animal cruelty and done solely for the owner's benefit.

I don't think there is much you can do about the situation. You can try to educate her but sometimes you can talk until you are blue in the face and it still won't make a difference.