Du'a for your mother

رَّبِّ ٱغۡفِرۡ لِي وَلِوَٰلِدَيَّ وَلِمَن دَخَلَ بَيۡتِيَ مُؤۡمِنࣰا وَلِلۡمُؤۡمِنِينَ وَٱلۡمُؤۡمِنَٰتِۖ

Rabbigh-fir lee wa li-waalidayya wa liman dakhala baytiya mu'minan wa lil-mu'mineena wal-mu'minaat

My Lord! Forgive me and my parents and him who entereth my house believing, and believing men and believing women

Qur'an 71:28 (Nuh)