I'm doing a bit of research on giftedness and stumbled across THIS chart, and it all became clear. Absolutely CRITICAL reading if you are facing the "are they or aren't they" conundrum.
I think I'd been fobbing myself off with the fact that Annika might just be on the clever side of ordinary, whereas she ticks almost every box in that middle column.
Mindblowing stuff. The thinking has clearly come from THIS guy, who actually explains it AND gives references. Lots of reading for both parents and teachers on his website, really practical stuff for dealing with "challenging" kids.