Disc brake CX bike for a 4'10" rider

 Yes, it can be done and here's a finished example. A way to get standover for a rider this size is a reverse-curve top tube.I know that some builders won't go to these extremes but this little shredder is what custom bikes are all about-finding solutions for folks that don't fit on store-bought production bikes.

The disc brakes really simplify the cable routing issues that usually plague bikes this size. The build includes some nice stuff like Brooks saddle and handlebar tape, King headset and White Industry hubs.