The frame sounds very small, much too small for your friend. It would most likely fit someone just around 5' or so.
As with anything you need a proper fitting with a qualified fitter or at the minimum in a bike shop where you can actually sit on the bike in question. Most manufacturers made and measure their bikes differently. So on one bike you may fit a 51 on another 53 but the most important measurement is the top tube length not standover (lots of threads on this forum about fit). Your friend must be comfortable on the bike, be able to reach the brakes, shifter etc and in this case, not be all bunched up. I would bet the top tube is going to be very short on this bike, especially with compact geometry.