Originally Posted by Bevdeforges

Assuming your neighbour is dead and the 3 children inherited the house in indivision, there's nothing you can do. The last third of the house actually belongs to the children of the dead brother - not to his wife. Though, if the children are underage, their mother controls their interest in the house in their name.

If the children of the deceased brother were adults, you'd have to get the agreement of each one of them for the sale before the property could be sold. (Though it would eliminate the influence of the sister-in-law.)

French inheritance law is a real mind blower to us anglo-saxon types.
Cheers,
Bev