I straightened DD's hair (for the first time) - she is mixed race
& it was great, you could comb it & brush it so easily apart from the last half inch which needed a trim as it was all split ends
So we had it cut - & it was lovely.....and then she washed it & it went curly
& it's all different lengths 
Hairdresser will re-cut on Monday no problem - but should we have anticipated it?