They usually live on the other side of the world - they're here for a visit. My brother and sister-in law have one DD and one DS.
I really get on with my sister in law and I'm actually closer to her than to my brother. However, I feel that enough people stick their noses in and tell parents in general what they should and shouldn't be doing when it's the parents' choice. However, I did study a lot of child development in my psychology degree and attachment theory (albeit in adults) was crucial to my final year research project.
I think my niece has an avoidant attachment to my sister-in law. My sister-in law visited her parents with her DS for a week. My niece didn't ask after her mummy once in that week of separation. Not to me, not to my brother and not to my mother. This struck me and my mum as quite odd. I have noticed quite a few things my sister in law does 'in order to promote independence' I don't think they have promoted independence I think they have just taught my niece to internalise her feelings/ not outwardly show pain to her mum as she knows her mum won't console her.
Additionally, my sister in law sees a naughty little girl who is very rough with other children. I see a little girl who is acts out in order to get attention and who is unresponsive to other's emotional needs (I know a large degree of this is also her age but my sister has a DD the same age and they are so different in this regard) because her own are ignored. She was actually really well behaved for me for the week my sister in law left and started acting up on her return (but then was well behaved again when she was left soley in my care)
I am also worried about the constant use of the word naughty. Even though with avoidant attachment style there tends to be a positive view of self (and negative view of others) I feel that she might internalise that label. When I knocked something over by mistake my niece's first reaction was 'you're such a naughty girl auntie truffle' mimicking how her parents talk to her (not differentiating accidents and when they give her confusing instructions e.g one meal time she was playing with her food a bit and my brother came over and directly asked her 'Are you being naughty?' and when she started to answer he then chastised her for talking with food in her mouth)
I don't want to over step my mark and make it a big deal or appear to criticise my brother or my sister in law but equally I'd feel bad not to say anything when I'm sure it comes from lack of knowledge on the subject rather than lack of caring. I have thought of maybe giving her a book on attachment theory and just say this is something I find interesting. My nephew actually appears to be securely attached but she has regarded him as a 'good baby' and I think finds it easier to be responsive to him. I could also casually mention that the word 'naughty' is banned in the UK in most nurseries and schools and explain why.
What do you all think? Or is there another approach? Or should I just ignore my concerns?