The fact that your father failed to leave a Will expressing the desire that your brother could live there for his life means that any desire he may have or not expressed to that effect is irrelevant and not a factor.
Living in a house is not enough to get an interest in that house. Everyone needs to live somewhere and to do that we all have to pay rent, bills etc. To get a separate interest in someone else's house a contribution has to be made in money or monies worth (building extension etc) that increases the value of the house
In the absence of Will any surviving wife would be the administrator of his estate otherwise all his children would be next in line. Generally speaking 2 of you should become administrators. The beneficiaries of the intestacy ( the children ) can decide to delay sale of the house to let your brother live there but they can insist on terms such as rent, maintaining building insurance , local taxes etc or if that is not acceptable to your brother sale can be forced.
I hope this helps any further points please respond, I will be happy to reply.