If there is no clear executor authority or the disagreement is severe enough to stall the estate, any beneficiary can apply to the Court of King's Bench for direction, and in some cases a co-owner can force a sale through the court rather than remaining stuck in a standoff for months.
Before it reaches a legal fight, an independent valuation often defuses the disagreement, since siblings frequently disagree less about whether to sell than about what the house is actually worth, and a hand-reviewed number both sides can see tends to move the conversation forward.
A lawyer experienced in estate matters can outline the specific options available for this estate, which vary depending on the will's wording and how many beneficiaries are involved. Get your hand-reviewed valuation from Joel Dyck.