If your sister’s daughter is your niece then her child would be your great niece or your great nephew, making you their great aunt or uncle. Additionally, if your sister is your half sister, this would make her child your half niece or nephew, according to the law, that child would still be considered your biological niece or nephew and therefore you would be well within your rights to refer to yourself as their great aunt or great uncle.
Since this child is legally considered to be you great niece or nephew, whether your sister is your complete biological sister or half, according to the law you could still have a claim over the child and would be legally considered the child’s guardian if anything were to happen to the child’s parents. However, if you were not willing to take that responsibility, that the said child would become the legal ward of the court.
Furthermore, your age does not have any bearing on whether you are a great aunt or a great uncle. The terms aunt or uncle has often been used as a term to distinguish between older generations. Young children are sometimes expected to refer to older adults as their aunt or their uncle as a sign of respect for their age. However, if this is the case, this does not make you their biological aunt or uncle and you would not have any claim for them biologically in a court of law if anything should have happened to the parents. Their biological family would have first priority, unless the will of the parents’ stated otherwise.
Since this child is legally considered to be you great niece or nephew, whether your sister is your complete biological sister or half, according to the law you could still have a claim over the child and would be legally considered the child’s guardian if anything were to happen to the child’s parents. However, if you were not willing to take that responsibility, that the said child would become the legal ward of the court.
Furthermore, your age does not have any bearing on whether you are a great aunt or a great uncle. The terms aunt or uncle has often been used as a term to distinguish between older generations. Young children are sometimes expected to refer to older adults as their aunt or their uncle as a sign of respect for their age. However, if this is the case, this does not make you their biological aunt or uncle and you would not have any claim for them biologically in a court of law if anything should have happened to the parents. Their biological family would have first priority, unless the will of the parents’ stated otherwise.
