I'm writing a short story set in an English house party of the late 1930s (1938, to be precise). Most of the details are covered well enough for my purposes by Emily Post
and the Gosford Park
script book, but I can't find any information on the presence of older children (thirteen-years-old) at such affairs.
For example, would they be invited at all, and if so, would they be fed separately to the adults, relegated to a nursery or what-have-you? None of the sources I've found mention children at all, which implies that they weren't welcome at house parties, but if anyone can tell me otherwise -- or at least hint at some flexibility in the etiquette, I'd be very much obliged.
ETA: And now I have all I need; thank you very much to those who commented!