Leila Aboulela said this quote

Can I aske forgiveness for someone else, someone whose already dead?Yes, you can. Of course you can. And you can give charity in their name and you can recite the Qur'an for their sake. All these things will reach them, your prayers will ease the hardship and loneliness of their grave or it will reach them in bright, beautiful gifts. Gifts to unwrap and enjoy and they will know that this gift is from you.