I do wonder as khun kanittaya as well, but I will give you some comment. Before 55 he will get job seeker allownace but it might limits time and he need to sight the paper now and then If he is being unhealty, he might get disablity living allowance. After 55 he can get early retire from his company when he reach 60, he can get pension credit and when he is in 65 he will be able to get state pension.
Benefit for you sister is depending on where she lives what visa she has hold. If she live in the UK , hold ILR visa and not do any work, her husband can claim for her as a spouse. She will get nothing if she only holds spouse visa.l