What sounds strange to you in the title? Nothing? Something?
In English or German, addressing your child with the words “my daughter/son” instead of their name is not common and sounds rather odd to me. In Spanish, however, this is very common. I spent about 17 months travelling through Latin America. Parents frequently talk to their children addressing them as “mi hija/hijo” (and it sounds perfectly normal to me in Spanish, but just not in any other language that I know).
At the same time, mi hija/hijo is also commonly used by people when addressing a person young enough to be their daughter/son (without a biological connection).
I wonder how these “phenomena” came about and may be connected to another…