nephling
The gender-neutral term for a niece or nephew (by analogy with sibling).

Nephlings are the delightful creatures you can adore and play with and who look up to you, but whose diapers you don't have to change and whose tantrums are not your problem.  The warm feeling you get from seeing your nephlings is unconscious gratification that your genes are being passed on (indirectly) to the next generation, without any effort of your own.
How many nephlings do you have?  How many of those are nieces?  Anyway, my nephlings are cuter than yours.