I agree. At 11, I would be concerned if my child WASN'T swearing! It's now normal for an 11 year old to be using the word "FUCK" alot, so I would wonder about one who wasn't saying that on a regular basis instead of worrying about it if he/she was. Let kids cuss! They qare going to eventually anyway.
My daughter is 6 now and we approach her swearing EXACTLY the same way that you do. She is in 2nd grade now and knows that swearing is not appropriate at school. She also knows that it isn't appropriate at certain relatives' houses (one set of grandparents; at the other set, it's ok). At some relatives' places, it's perfectly ok. At some of her friends' houses it's no problem; at others' it would not go over well. Stephy (my daughter) knows that swearing is entirely and completely acceptable at home at all times, so she exercises that right with a full range of expletives, without punishment, at home. She has learned where it is appropriate and where it isn't from growing up with it from day one of learning to speak.So-called "swear words" have always just been normal words for her, with a healthy sprinkling of knowing when and where to use them properly (for example, she knows, even at home, that it isn't acceptable to swear AT someone; that is literally her only limitation on it. But "conversational swearing" is perfectly fine and normal at home all the time). She has never crossed the line or been inappropriate, and I don't suspect that she ever will. She is growing up with a full range of colorful words at her disposal, but also with the intelligence to know when to use them. To us, that is the way it should be and we are perfectly content with letting her swear to her heart's content anytime she wants at home.