(decedent's holographic will left decedent's residuary estate to decedent's sister "with the understanding that she will take care of my mother"; decedent's brother was intestate heir and filed motion to remove sister as co-administrator on grounds of breach of fiduciary duty; court held that will language was precatory and conveyed decedent's residuary estate to sister in fee simple; language did not result in creation of testamentary trust or conditional bequest).