Praise God.
Well, The how part is up to God, and all things are possible to those that believe.
To someone that created the mountains and filled the earth with the ocean. Took dust and formed a man, breathing life into him. Could at a Word shake this earth from it's foundation, knocking down every building that is standing.
Your mother's healing is not a issue with Him.
your mother is Born again. Ask her what she would like from God. She will have a clear mind, and she will answer you. If she plans to stay around then no problem for God, If she is tired of the pain, and fight, then God will honor that also. It's not like she will die, but just move somewhere else and wait around for use to get there. You will see her again soon enough.
I take prayer and my faith in something very seriously. I just don't want to pray against your mother's wishes.
For now, Peace and comfort will be upon her, your mother's mind clear. NO FEAR, but peace. In Jesus Name!!!!
God Bless you Sister, all spiritual blessings abound toward you with your spirit strengthened by the Holy Spirit.