What would want a social worker to do for your mum? They are really there to help people access other services, and it helps to have an idea to start with of what you'd like those services to be.
It also depends on the extent to which your mother acknowledges her illness and its associated problems.
Your first call might be to the psychiatric nurse, Ask him or her what's available to your mother in terms of support, and how she might access it. Perhaps there's a work training scheme she could get on to that's especially tailored for people with mental illnesses.
Another idea might be the sort of place I used to help out at - an social club where members could chat, have tea/coffee, take part in various activities (I used to run a poetry workshop at ours - reading and talking about, that sort of thing). Sometimes we had speakers in, and often, members would get involved in the running of stuff. Our group was at the local FE college, supported by the mental health charity, MIND, who were an invaluable source of support and advice to workers and members alike.
http://www.mind.org.uk/