What the actual F do I do?

My husband told my SIL she isn’t allowed any contact with our child because of how disrespectful she’s been towards me and yesterday at 1am we got a text from her saying how sad she is now that she won’t have a chance to be in her niece’s life and that she’s also lost her brother. She has never spoke to me ever. She’s been telling people that I don’t like her which everyone has reassure her that not true and asked her if she has actually bothered to get to know me and this was 6 months ago. She hasn’t bother once even when I’ve said hi to her, she would fully ignored me. I live far from my family so I rarely see them and this morning I told my mum what has been happening and how she texted and never even mentioned wanting a relationship with me but only mentioned my husband and child like I don’t exist. I have been corned before by my in-laws about another situation last year and that really upset my mum because she wasn’t there to support me. My mum said that she’s really upset now because I’m here on my own and it will literally be 10 against 1. My mum has made it very clear that if my in-laws try to corner me about this situation to just let them know that we are going to organise a day where my parents can drive down so my parents can be there to support and am not on my own. I know my mum means well but I want to avoid getting her involved because my husband said he doesn’t want my family to think his allowing his family to mistreat me. I know my husband has my back but it is still his family and I don’t want to ruin their relationship. But I know if anything happens my parents would go above and beyond for me. And my mum is worried that they might think because my parents is far they won’t bother getting involved. My mum is a full on mama bear and she’s seen me cry too many times because of them not respecting my boundaries.