As a person with a similar story I can totally relate.
You might feel like.."what can I do? I'm only one person..How can I change this?"
I know. We all feel like that in situations like this..
But there are actually some things you can do.
First of all you can always keep the faith. Always believe that your mom is going to get better, that she's is healthy.
Say to yourself "My mom deserves to be healthy. She is healthy. She is strong and happy. My whole family is happy."
You know the drill..Use the LOA for your mom the same way you're using it for yourself.
You can heal her with the strength of your thoughts..especially if they come deep from the heart and are pure. Use all of your love to heal your mom. It's similar to reiki just without puting hands on your mom..you put your hearts' love in her body.
Did you ever hear about an energy ball? It's when you send your energy to someone. Well you can send healing energy balls to your mom.
Then as someone already suggested you can do the Hooponopono practice. I don't know if it works from personal experience but people only said great stuff about it.
The other stuff I have for you is a mantra..That I can tell you from my own experience works. Even in life threating diseases. It is usually a mantra people say for those who are bed ridden aka can't do it themselves.
It goes like this: Om joom sah (your mum's name) palay sah soom on.
Imagine your mom being healed by a white light.
You cold also write Kunjitha Padam Saranam on a piece of paper and put it under your mom's pillow. This can also be chanted..but i figure it's easier to put it under the pillow.
Actually there's many things you can write on a paper and put in under your mom's pillow..including the Hoʻoponopono.
It's basically something to send strength and healing power into her body.
http://www.sikhnet.com/gurbani/audio/15-ant-na-siftee -> listening to ant na siftee you can reduce your family's karma. Meaning breaking your family's misfortune. Unfortunately i don't have the mantra lyrics to chant along..but if you want i can find it. If you wish to download it..search online for ant na sipftee mirabai ceiba. When you remove someone's karma you remove all their trouble.
One great thing that also helps..Is lifting your family's atmoshpere. In these times this might be hard (as you said your family members aren't that cooperative) but if you could do this it would also help your mom.
I know, my mother is also very skeptical..but when she saw the results i had from the positive thinking she changed her mind. she also stopped always talking about her diseases. The basic stuff you need to do is at least not talk about the disease.
I also tried persuading my family with success stories other people had..Basically you need to fuel their minds with faith. You need to be stern and persuasive. Face your mother with a smile and fuel her mind with positivty.
People are skeptical by nature so they always need proofs of something working.
I'm sorry if my post was too long..I just wish I can help you in my best way possible. If you have any questions or just need to talk to someone please feel free to contact me..I will always be available.
I am sending positive energy, positive vibes to your family.
A healing energy and pure love energy to your mother. I believe she is healthy, she is strong, she is healed.
She deserves to be healed and happy, she deserves to recover.
I am sending all my inner resources to your mother, to your family and you.
I am sending faith and mental support to you.
I believe in your family's happiness and am grateful to the universe for granting our desires to make your mom healthy again.
I am grateful to know your mom is healthy again.
Much love and always keep the faith!