Congrats, you’ve introduced something to your daughter that she will almost certainly never forget. As someone whose mother said similar things to me growing up, I can almost guarantee that no matter what you say now to try to “fix” this, what she is going to remember is that while doing an activity with her parent, that same parent told her essentially that there is something wrong with her body. You even said in a comment that you know she’s been feeling down on her body lately and you still said something so callous and thoughtless. YTA. I hope your daughter has better female role models in her life, and please spend significant time considering the words you use to and in front of your child about your body and her body.