If you are not very advanced, you are limited in this sense. But also don't doubt your influence and what can be done. Firstly, I would contact Baal-Zevulon. With his permission I would vibrate his name into the loved one everyday with specific affirmation of health.
You need to refrain from feeling so much empathy, as you'll connect with the disease. You need to know if this is a fated or other sorts situation. Regardless, Satanama, our Gods name vibrated as well plus a lot and I mean a lot of energy inhalation needs to be done.
What you are essentially doing, is giving resources for your loved one to heal. The outcomes of this can have a very strong backlash, which can create illness in yourself as well, as also being empathic, you'll be drained and also share the suffering.
This is not how it is supposed to be. As such you need more than ever to keep your optimism high everyday, along with high energies. When you apply energy on the loved one, you do it by evocation, gathering, never from yourself!
After every appliance, please clean yourself very very powerful and also use mantras if needed. Such as Agni.
Also, you need to make it clear and try to make your loved one think positively and accept the outcome of healing. Without this, healing can be very hard. When you inhale energy by the foundation meditation but on her, do it from the outer space or from a source of power, like the sun.
Given also the stage of the cancer is spread, specific techniques and or focusing is relatively unimportant.
Only if the doctors give a specific timespan, or it is known of the outcome in a undesired end, only then with the help of a Demon, you could try very gentle to raise energies of her spine and awake her Serpent. But only then as a last hope.
Regardless, an outcome such as the above can only be delayed even with a success such as that. So preferably do not think about it and hold on to optimistic values.
I wish you health and success to you and your family. Stay strong.