<is there a collective/descriptive noun for nieces/nephews?>

Lipton's wonderful collection of collective nouns "An exaltation of larks" doesn't seem to include nieces/nephews but does have:

a descent of relatives

an expectation of heirs

an ingratitude of children

a caper of kids

a leer of boys

a giggle of girls

and [off topic?] a mutter of mother-in-laws.

Incidentally, David108, do your older friends ever refer to you as DavidCVIII?