Once the baby is born, you are considered to be its grand aunt or grand uncle.
Your "great niece"
yes she is
Great niece's baby is your great-great niece or great-great nephew.The system works like this:Your niece's child is your great niece/nephewYour great niece's child is your great great niece/nephewYour great great niece's child is your great great great niece/nephewYour great great great niece's child is your great great great great niece/nephew...
Your niece.
The great aunt is the great niece's baby's great-great aunt.
No.
yes she is
Niece
Isys
If your great-niece has a baby, that baby would be your great-great-niece or great-great-nephew. This relationship is one generation further down from your great-niece, making you the great-great-relative. Essentially, you would be the great-great-aunt or great-great-uncle to the child.
a niece or nephew
Niece.