Mum with lung cancer

Hi, 

this is my first post I’ve had a friend suggest come on here to get support, help and advice 

my mum got diagnosed in March with lung cancer which had already spread to 2 parts in her back previously to that she had just been struggling with back pain no symptoms to the lung cancer, she had an operation on one part of her back to save her mobility, she came out of hospital the weekend before lock down I came down to see her for a day stayed over then lockdown happened so I made the choice to stay at my parents home I ended up taking over all her care from then on, then in may on her birthday we couldn’t wake her up and this went on all day my dad phoned for an ambulance and found out her oxygen level had gone to 55, previously to this she had had 2 sessions of radiotherapy on her back and had been talking about starting chemotherapy. 
while she was in hospital we had found out the cancer had spread the doctor was saying she was weak and thought she only had days left also from her discharge notes found out she’s at stage 4 

when she came out of hospital she has struggled with her leg and not been out of bed since and I’m now noticing more things happening like the confusion, hallucinations even forgetting things and last week her hands started shaking and she spilt her brew over the bed and now noticed she gets the shakes when eating as well and her temper coming out and it’s me who gets it with doing all the caring 

I’m wondering if the shakes is another sign it has spread to Her brain 

thank you for any advice