I am 5' 9" and around a size 10/12 and I usually buy 32 to 33 inch at least. But I never wear heels, only flats so they don't need the extra bit to go over heels iyswim. You would be ok I think. I have hips and bum, am not beanpole. D
They look a bit weird when you first look in the mirror as you are used to seeing wafts of bootcut fabric about (thighs!!!) But I quite liked them. I had Converse on and looked like something out of the Ramones, ha.
Will get dh to cast his expert eye at w/end I think.