Advice really depends on where Angelus's sister lives - I'm guessing in UK, but services vary between areas. Contacting diabetes specialist nurse would be a good start - I've never heard of diabetes social workers, although there are psychiatric social workers, and it sounds like mental health is a big issue here, plus bing on oxygen might mean there's a respiratory specialist nurse and consultant as well. Local council may be able to arrange an occupational therapy assessment, eventually, and perhaps supply some aids and adaptions (depends on landlord if property is rented), and possibly some adult social care, although spending cuts have meant cut backs in this area; if sister is over 65, might be easier as she counts as elderly, and if over 70 or 75 might be easier to qualify for help. In addition, worth asking Citizens Advice Bureau or local welfare rights advice centre to check that she is getting all benefits - as she now lives alone, she might be entitled to council tax rebate etc.