my nieces has moderate special needs, she is a sweet girl, and all the family cousins get on well with each other. When she was small she was a bit light fingered with my daughters belongings. Or she would go in her bedroom and break or tear personal things like necklaces.
My BIL was apologetic but found it difficult to stop this impulsive behaviour. So we learnt over the years to sweep the house of anything she might be tempted by or destroy and hide it before she came.
For a long time she seemed to have grown out of this, and is now past her teens, although still not capable of independent life without support.
We had her over for a sleep over with all her cousins and they had a fantastic time. My daughter left her make up on her bed, the stuff she uses every day and is has now gone. This make up was worth over £100 and some of it was saved from christmas and birthday money and some my mum brought her together on a day out.
We cant tell her father, it wont end very well. there wont be any confession of guilt from her because although she grasps that she had belongings, other peoples are a bit 'fluid'.
If we tell BIL it will end up him getting cross with us for the whole situation,and its not worth it.
my daughter is very upset, and I feel so angry and frustrated with the whole thing. I cant let her come in to our home again as we cant trust her.