Your mother. If you want your girlfriend to be able to make decisions for you if you become incapacitated or if you want her to inherit your property then you must execute legal documents to that effect. You should consult with an attorney who can review your situation and explain your options.
Not if you are the mother. cousin, or basically family blood.
Your mother, but both parents are next of kin
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 the girlfriend can be considered his common-law wife and the state where they reside recognizes the validity of such a marriage, she can claim next of kin.
The next of kin is usually a child and not a sister. For example, if a mother passes away, the next of kin would be her husband and then her children.
The mother or father or legal guardian of the sisters. if there is no guardian the sister is next of kin.
In most cases the next of kin would be the spouse. If there is no spouse, children would be considered.
Mother, if you mean wife of the deceased husband.
The next of kin can visit their kin in the hospital, can make decisions for an unconscious person, can inherit property, can arrange for a funeral.
Your adult children.
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.
Legally, not unless named in the will.