I’m a single parent with an 8 year old DD, who is autistic. She attends an SEN school and struggles to have a conversation etc (this is relevant to this situation).
DD doesn’t see her dad anymore due to DV, so my mum has her every now and then to give me a bit of a break. My sister lives at home with my mum (she’s an adult in her early 20’s).
They don’t particularly get on at times but in general everything is usually fine, have the odd argument here and there and that’s it. I’ve heard through the grapevine (my sister told another family member who told me because it involved DD) that the last time DD was there without me (within the last 2 weeks) that apparently they got into a really nasty argument where my mum went to hit my sister and that apparently DD got really upset by it.
DD isn’t very good at verbalising so asking her has been impossible. I know that I need to address this situation but how is best to do it without causing more arguments between everyone? I mean I’m sure as shit going to kick off if this is true because they know DD has already watched her dad behave like that to people and I’m not letting them behave that way in front of her too, but I also know the minute I tell my mum that I know this, that she could potentially be VERY nasty to my sister who is usually the innocent party in it all (my mum has a vendetta against my sister for pretty much no reason, she always has gone).
What is the best way to handle this?