Correction - your brother does not have to show he was financially dependent on your mother. Under the Inheritance (Provision for Family and Dependants) Act 1975, your brother falls into a class of claimant (ie son of the deceased) who have an automatic right to claim. He does NOT need to show dependency. However, it is much harder for an adult child who has the ability to work (ie no disability) and who was not promised anything by the deceased to mount a credible claim.
There is not a thing you can do though. Your mother has done everything she can for now.
Unless your brother is successful in a claim under the above mentioned act he does not have access to the house or half the estate (unless the Will permits it).
It terms of you having time off, there is no right to this, nor is there any right for you to claim any expenses. Up to you and your mother to come to a personal arrangement.