Answer: assalamu alaykum
It would be permitted for you to inherit from your non-Muslim mother in this case.
Though the four schools state that this would generally be impermissible, there is (a) a difference of opinion among some of the salaf as to whether this rule applies to a Muslim inheriting from a non-Muslim and (b) some contemporary scholars have ruled that a Muslim can inherit from a non-Muslim when this is legislated and carried out by a secular, non-Muslim state.
Among the scholars who argued based on the above are Mawlana Ashraf Ali Thanawi and Mawlana Zafar Usmani. (Imdad al-Akham, 4:627-28)
[Ustadh] Salman
Checked and Approved by Shaykh Faraz Rabbani
Ustadh Salman Younas was born and raised in New York and graduated from Stony Brook University with a degree in Political Science and Religious Studies. After studying the Islamic sciences online and with local scholars in New York, Ustadh Salman moved to Amman. He studies Islamic law, legal methodology, belief, hadith methodology, logic, Arabic, and tafsir. Ustadh Salman’s personal interests include research into law/legal methodology, hadith, theology, and political theory, government, media, and ethics. He is also an avid traveler and book collector. He currently resides in Amman with his wife.