There is no issue, as it is very unlikely that you share a common ancestor, there is no law to prevent it.
You and your father's niece are first cousins.
They are first cousins once removed. Your niece's children and your grandchildren will then be 2nd cousins.
They are cousins.
Your granddaughter and your niece's son are second cousins.
You and your mother's niece are first cousins to each other, so your and the niece's daughter are fist cousins, once removed.
Your daughter and your niece are first cousins Your daughter and your great grand niece are first cousins, twice removed.
(1) Your niece is the daughter of your sibling (2) Your niece and your children are 1st cousins (3) Your grandchildren and your niece's children are 2nd cousins (4) Your g'children and your niece's g'children are 2nd cousins once removed
Your niece and one of your grandson's parents are first cousins. That makes your niece a first cousin once removed of your grandson.
Your daughter and your niece are first cousins to each other.
Your children and your niece are first cousins to each other.
Your niece's child and your grandson's child (your great grandchild) are second cousins, once removed, to each other.
Your grand niece and your grandson are second cousins to each other