Generally, if both parents are deceased the siblings or issue of any deceased siblings would be next of kin. If there are no siblings or issue of siblings the next of kin would be collateral kindred and that can get more complicated. There are charts that show how to determine collateral kin and the state laws of intestacy control who inherits in an intestate estate. You can see more at the links provided below.
The standard of intestate succession would say that the daughter would inherit the estate unless the will says otherwise. Generally however, minor children cannot be disinherited by will.
Without a will of intent all inheritance will go to the next of kin. The order of that is wife, father/mother, son and daughter.
next of kin would be eldest child
Mother, if you mean wife of the deceased husband.
Whether or not a step daughter is next of kin depends on a variety of factors. If there are no other closer relatives, then it could be the case.
Your mother, but both parents are next of kin
Yes, your step daughter or nephew can be your next of kin. Next of kin is typically a family member that is surviving.
No.
It goes to next of kin
If a person who has no spouse or children dies the living parent(s) would be the next of kin for purposes of inheritance. You can check your state laws of intestacy at the related question link below.
The mother AND the father are a child's next of kin. Next of kin is determined by legal adoption, marriage and blood. If a child's parents are deceased their next-of-kin would be their siblings by blood or by legal adoption.
If you are speaking of the relative or relatives entitled to share in your property if you die intestate (without a will) then if you are unmarried your parents are your next of kin. If they were deceased then your sister would be your next of kin. In another sense they are all your next of kin. See related question link.
If the POA is Durable and granted the right to make medical decisions then the daughter can make those decisions. Her power would take precedence over that of her father as the spouse. When a person dies the POA is immediately extinguished and the husband would be the legal next of kin for decisions regarding the burial arrangements.