Is it a frustration thing or a gee-this-is-a-funny/interesting-noise-to-make thing do you think?
Not sure, still trying to work it out. She has just gone down for a sleep though (extremely rare for her to sleep during the day especially this early) so maybe a frustration-i'm tired squeal? The other day squeals were at dinnertime- which could have been tired one too.... mmm, might be on to something.