My dad has raised me so that, he lets me swear at home but I can't take it too far and not to swear at him (or anyone else unless needed) unless we're messing around. I will never agree if someone says children swearing is based on bad parenting, hell, 90% of the time the parent has no idea the kid swears at all. Oh and I hear 8 year olds swearing, it just spreads around,1 little kid swears because they heard a teenager say it, then the others pick it up. It's a bit like a cycle. I do say though when you have little kids swearing at you, it's quite disturbing.
I personally don't swear very often unless I'm extremely mad. On the subject of what I think of others using it I personally don't mind when people do, but there's a time and place for everything. There are many people who swear so much they don't know how not to when it comes time to not use it. My brother for one has lost a lot of jobs because he doesn't know how to control his swearing and it just flows out naturally. When you're with your friends or out in public I don't see a problem with it although others might. In a business atmosphere you need to learn to talk respectfully without swearing, unless you work in a job where no one cares.
Edit: Also my opinion on kids swearing is I don't really care. I've heard my daughter who is 11 swear a few times here and there, but I don't see it as a big deal. She doesn't do it at school or in public just around the house and it's not very often. As long as she knows when it's not OK to use that language it's fine with me.
How do you know she doesn't swear at school? I don't mean to sound disrespectful but even though she is your daughter, if she tells you she doesn't swear at school, I'd highly doubt it. It's like I said, 1 kid picks it up, (Daughter) and spreads it to the other kids, then they all know it, but don't know when to use it.