I've noticed that sometimes family members are referred to in a weird way(to me) in speech. For example, instead of "I will talk to my mum" or "Give this to your dad", I often hear "I'll talk to mum" and "Give this to dad" instead (no, whoever that talked like this surely isn't my sibling). After asking a friend of mine how his daughter was (she was in hospital), he replied "Daughter is doing well"(again, not my daughter in any sense of the word). Both of these examples sound very awkward to me. I'm wondering if this usage is related to "the wife" (instead of "my wife") or using "sir" or "miss" in third person ("miss asked me to tell you...")? What other people do you refer to in this way?
The examples with mum and dad are common usage, and I suspect that's because they are forms of address. My daughter Naomi calls her mother mummy, so when I am talking to my daughter, I also refer to her as mummy. This started because if I'd said Helen or my wife then Naomi wouldn't have known to whom I was referring; but, of course, it becomes established after a while and long outlives its purpose in that respect.
This does seem similar to sir and miss: these are also forms of address that then get used as third person references, though this usage is less well established, and teachers in my experience have discouraged it whenever they've heard it.
The daughter example you give sounds very unnatural to me. I suspect it was a succinct way of writing it in a text message or similar.