A parent or sibling. Other than that the courts would make any decisions. * The ex-spouse if he or she is the biological parent of said children, a divorce does not invalidate parental rights. If that were not possible the next of kin in progression would be an acceptable adult sibling of the minor children, maternal grandparent(s), paternal grandparent(s). If none of those applied the court would request voluntary guardian petitions from the siblings of either or both biological parents. Appointed Godparents do not have automatic legal custodial rights as is sometimes believed.
If there are no other legally binding arrangements made, the matter would probably be decided by the Order of Precedence that is applicable for the country of residence. In many western cultures (including in the U.S.), an unmarried person's parents would be the closest next of kin.
The court must appoint a guardian.
No. Although next of kin is an inexact term depending on the context, a fiance is not next of kin. An unmarried adult's (who has minor children) children and parents would be considered next of kin. See related question link. A fiance would have no legal rights unless the decedent had executed a document granting legal authority.
Not necessarily. If the widower is unmarried, and has no children, but has parents or siblings that are still living - then they are the next of kin
Their parents or other family members would be their next of kin.
In a case of no will, the next of kin has priority. Unless there is a will, the unmarried partner will not have any rights.
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.
The mother or father or legal guardian of the sisters. if there is no guardian the sister is next of kin.
In the US and the UK a minor child's next of kin is her parents. It doesn't matter whether they are married and the law favors neither one. See the related question for a more detailed source for inheritance from intestate estates.
Generally speaking, if the patient has children (or a spouse and children), they are the legal next of kin. If no children (and no spouse), the parents are the next of kin.
Your next of kin is your adult child or if your child is a minor, your parents.
The children would be the next-of-kin, or more correctly his heirs at law, for purposes of inheritance. The mother would be next-of-kin if he was unmarried and childless. If he was seriously injured and cannot speak for himself and the children are minors his mother would likely be considered his next of kin. She would be favored by the court for appointment as his guardian. He may list either as beneficiaries of his property (estate) in his will, and it can be contested by either party in probate court. See related question.
If you are not married and your children are under 18 then your next of kin is either your parents or siblings.
The children of an unmarried decedent are his legal next of kin. You can check the laws of intestacy in the UK at the link provided below. On the first page look for the link at the bottom that will open a chart.