Ok so is is normal would you say for your mother in law to call your daughter a nannys girl but on quite a regular basis. She doesn't say it every time but it is most time we see her. Examples are:
Walking through her door and her saying hello nannys girl, you're nannys girl you are, yes you are. While DD is in my arms and before she even says hello to me and dp.
Saying it randomly to my DD.
Saying to family members that she's a nannys girl
Saying to DD in front of me that she may be a mummy's girl but she will be a nannys girl when mummy goes back to work. She will look after her for 1 day.
This makes me feel uneasy because he says it often, not all the time but she does say often that she's nannys girl. To me she is a mummy's girl and she's also a daddy's girl, I don't want her to ever be 'her girl' because she's not her child. How would it make you feel.