Wills, probate, letters of administration, powers of attorney
OK see a solicitor for advice about contesting the will, he can give you an idea if there is any chance and possible costs.
Fairness is rarely a factor, the family provisions act applies as does considerable case law on the needs of the parties. You may need to pay your solicitor to obtain an opinion from a barrister as to the likely success or otherwise. This could cost you many thousands. The solicitor will be able to give you an idea on costs.