Income Support
Income Support (IS) is generally for people on low incomes who work less than 16 hours per week, but who do not need to sign on as unemployed. IS is available for single claimant or lone parent foster carers. For this purpose, a foster carer is not treated as in remunerative work, and therefore the 16 hour per week condition is likely to be satisfied, unless a second job is taken. As you would expect, this is a means-tested benefit, and therefore if you have savings of more than £16,000, you will not qualify for IS.
If you are married, or in a civil partnership (or live with someone as if you are) then you may still qualify for IS, but your household income would be considered instead. Unlike you, your partner would not be exempt from the requirement to be available for work. As a consequence, if your partner works full-time (which is defined as working 24 hours or more per week) then you will not qualify for this relief.