So 13yo DD fainted this morning before she had breakfast (in quite spectacular swooning style). She was pale and clammy, out of it for maybe 20-30 secs. Right as rain after 10 mins, no temperature. She said she had felt a bit sick and saw spots in front of her eyes before she "went".
DrGoogle tells me this is all fairly normal, nothing to worry about, probably low blood sugar or dehydration (the latter being particularly relevant as I'm always nagging to drink more). However this is a first so would be reassured by others' tales of swooning teens!