What brands have you looked at? I think most brands have a 48cm and sometimes a 44cm option these days. I'm 5'4" with short legs and ride an extra small Giant TCX w. As much as I love Giant, I have to say their women's CX bikes are built on the long legs/short torso stereotype, so the stand-over height is disproportionately high, and the XS still feels a bit too tall.