My stepmother is the personal representative of my father’s estate. She wants to give my father’s house to my stepbrother, who has been living there since my father moved into residential care and is also a beneficiary. My siblings and I oppose this. Can she do this?

No. As personal representative, your stepmother owes an undivided duty of loyalty to all beneficiaries. She cannot favor her son over another beneficiary. She must have the property appraised by an independent appraiser and she can then offer the house to any and all beneficiaries who wish to purchase it for its fair market value.