She must repent to Allah and ask for His forgiveness. Being rude or harsh to one’s mother is a major sin. If she manages to win her mother’s heart and get her to forgive her and be happy with her, this means that Allah will forgive her!

After she has repented, she must not dwell on it, rather move on, but never do this again.

Please advise a sister who is very depressed because she upsets her mother in periodic and strong arguments. She is experiencing a number of trials which become difficult at times so ends up in these situations unfortunately. She apologised, made taubah,given charity for her mum etc but feels this is not enough, cannot forgive herself and punishes herself.