Legal Question in Wills and Trusts in Florida

Not necessarily. First, you need to look at how the house was owned, was it joint tenants with right of survivorship, or was it a tenancy in common. That makes a difference. If it was owned as tenants in common, then your father's interest only goes through probate, and gets distributed to the heirs. If the heirs cannot work out an arrangement with your sister, then the heirs might file what is called a partition action which can force the sale of the house, so that the heirs get their share of the inheritance. A partition action is messy, and will cause harm to your relationship with your sister. Try and avoid it.