Over 75 still on DLA - health has deteriorated

My friend's mother was not migrated from DLA to PIP, due to her age. She receives the higher level Mobility component, and the low level care component. Her health has deteriorated over the last few months, with the onset of dementia, and her son has had to become a full time carer. He applied for Carer's Allowance, but was told that his Mum does not receive the relevant benefits (middle or higher care component). She needs round the clock care now, and has to be monitored so that she can not leave the house, she does not recognise that she is in her own home. He cooks all meals, washing, cleaning, taking her to medical appointments as needed. She has had a few falls and Paramedics have had to come and help to get her back on her feet, as she is a large lady, and also two recent hospital admissions.

From research, it seems that due to her being over 75, they will review her DLA, as per the conditions which were in place when it was granted. Please could you inform if they review the whole claim (mobility and care), or just the care compenent, as this is where the changes are? Thank you.