Ive gone no contact, Narc ex is hoovering via email through my mother HELP!

I will keep it brief. Ive gone non contact deleting my ex from all social media and not answering emails. Its working well. But she has started emailing my mother as we were dating for quite a few years and they built up a small relationship. I can see that the fake "front" she puts on for my mum. But my mum obviously cant because she has not gone through or witnessed the abuse i have. I have informed my mum that she is a Covert Narc but as all videos really relate to the actual person being abused, im finding it hard to find information or a good video to show my mum on signs to look out for and how she is being played and that my ex is slowly directing their contact negatively towards me. Such as the break up was all my fault etc..... any advice would be much appreciated.