When one of my grand daughters was about 3 I was staying with them and she said a couple of times "you don't live here", with a rather hostile look. Which was true, but it upset me. She said the same to her other Grandma, and she was even more upset than me!
As Gillybob said she's not a kissy-huggy child.
Anyway the next time I went to stay she didn't say anything hostile, but kept her distance, now (6 years later) she's ok.
I think it's to do with attitude to relative strangers, maybe insecurity, language development etc.
I'm almost sure she'll grow out of it, Danericbob, when she can understand that you're her Daddy's Mum.