Best thing I ever did back in 2012 was to leave a controlling partner. There was no violence, but constant put downs, especially in front of family. Everything had to be done his way. When I left it was like a weight had been lifted off my shoulders, and I realised I had constantly been walking on egg-shells in case I did something 'wrong'
Your friend needs to realise for herself how she would be better off, and as others have said you need to ask her to stop talking about him now, as all that needs to be said by you has been said, you can say no morel