In terms of what might be useful for you, as one who accepts the Buddha's teaching is...Sn 3.8: Salla Suttahttp://www.accesstoinsight.org/tipitaka ... .irel.html
... however, your mother may not share this world-view and as such, may not find consolation in it. In fact, it might anger her.
Whatever you do, best to regard her with compassion and endeavour to help her through her grief, using the Buddha's teachings to support yourself
(and thus making you of more use to her as a support).
“I hope, Anuruddha, that you are all living in concord, with mutual appreciation, without disputing, blending like milk and water, viewing each other with kindly eyes.” (MN 31)
What is the final conviction that comes when radical attention is razor-edge sharp? That the object of the mind is mind-made (manomaya). (Ven. Ñāṇananda)
"If you have always believed that everyone should play by the same rules and be judged by the same standards, that would have gotten you labeled a radical 50 years ago, a liberal 25 years ago and a racist today." (Thomas Sowell)