Forwarded answer from Abu Rayhanah AbdulHakeem Al-Amreeki hafidahullah

وعليكم السلام ورحمة الله وبركاته May Allah honor and protect you. Vulgar language, insults and other bad conduct is primarily due to ignorance of the correct etiquettes and unawareness of the harm it causes. Allah explains in His book that the Prophet peace upon him was annoyed and bothered by Insults. Thus, you must be patient and in a nice manner, explain to your mother that her speech disturbs you and that there is a better way. She may get upset when you inform her of what's appropriate, however, there's no other way. Try to tell her in a nice manner, not blaming but just to apprise and make her aware of the harm it does. Tell her that harsh speech from parents often builds barriers between them and their children. Whereas the child's fear of censure and blame makes him/her afraid and uncomfortable to open up and share their thoughts and troubles with them.