她爹:“你谢谢阿姨没?”小姑娘很可爱的说:“谢谢阿姨”That's good.
Then 她爹:“跟阿姨说,阿姨你真漂亮。”That's flirting, the girl doesn't like it. I think it's normal that a girl doesn't like her dad flirts around.
If it's her mom said “跟阿姨说,阿姨你真漂亮。”, it's perfectly fine. A man did that when wife is not around, not good.
I know my wife wouldn't like it.