Waaaaaay too complicated for an off the cuff response!
Whole series of big issues.
What did the will actually say?
Has Probate been extracted? If not, why not?
Has wife been advised of her legal right share? Time limits apply.
Do offspring want their share or are they all willing to disclaim in favour of mother?
Does mother have any grasp of the situation? If not, why are the family not getting on top of it?
If mother does start disposing of sites etc.,etc, and if she does see a solicitor , it will become reasonably clear reasonably quickly, what the situation on the ground is.
Friend should talk to uncle and see where it is all at. Also talk to all the family including mother. And cue huge family row.
Or just go straight to a solicitor and make themselves aware of the facts and the legal position without causing the huge family row.
mf