UGG boots (clic) only! Do they stretch?! ?

I'm looking into getting the gray clic short UGG boots and I'm having a bit of a difficult time. Since they don't have halves (i.e. 6.5) I'm stuck between 6 or 7. 6 is a little tight on me but I'm afraid 7 is too big and it'll look weird the lady at the store said they stretch a lot but she might be only trying to sell, so do they stretch?! Ive worn emu boots before but never UGGs