Younger vs. youngest
My husband and I disagree on the use of these two words. I say, since we have three children, two girls and a boy, that I can say that “Rebecca is the younger daughter, and the youngest child”. He says that since she is the youngest of all three children, that he can say she is his youngest daughter. I feel that it should be she is the younger daughter since there are only two daughters and of course, she is the youngest child.