Assalaamu Alaykum sister,
I'm sorry to hear about your aunt. Remember to read Qur'an on her as the Qur'an is a shifaa' for both spiritual and physical illness (read more
here). And generally try to increase in acts of worship Insha'Allaah.
May Allaah, Lord of Mankind, remove the affliction upon your aunt and send down cure and healing, for no one can cure except Him. May He (swt) cure her in such a way that no trace of illness is left, Aameen.