lady jane, i would sugget that she makes an appointment to see someone at the DWP They are pretty good and will help her with anything she needs to know about what she is entitled to.
You qualify for working tax credits if you work 16 hours or more per week, along with this comes help with housing tax benefit and council tax benefits, so she must go and see someone. Income support says you need �59.15 to live on per week. She will only get money for her child if they are 19 or under and still in full time education.
I hope things work out for her.