MIL has corrected me a couple of times now for saying this so wanted to get wider views… when talking directly to DH I have referred to her as ‘your mum’ e.g. ‘Your mum and I were just saying if the weather’s bad tomorrow we should go to XYZ’ - she then corrects me and says ‘Linda’. It feels artificial to say that to me and I don’t think I’m being rude? She doesn’t have a problem with me referring to her as ‘Grandma’ to DC. Obviously when I’m addressing her directly I use her name.