What it means
An executor is the person (or institution) appointed in a will to administer the deceased's estate. Their duties include locating the will, applying for probate if needed, collecting and protecting the assets, paying debts and taxes, and distributing what remains to the beneficiaries. Being an executor is a serious legal responsibility, and an executor can be held personally liable for mistakes made in administering the estate.
How it's used
Her father named her as executor, so it fell to her to apply for probate and divide the estate between her and her brother.