At last, Ashley and Mary-Kate Olsen’s clothing line the Row has spawned accessories. The twins signed a licensing deal with Linda Farrow to make sunglasses — an accessory they sport frequently — ranging in price from $325 to $390. They may soon add handbags and shoes to the Row, though they say they have their “hands full” right now. Farrow, which does sunglasses for labels like Bernard Willhelm, Dries Van Noten, and Jeremy Scott, chose to sign with the twins because, unlike many labels these days, the Row is going places. Also probably because they know that if Barneys doesn’t have to put the line on sale to sell the Row’s plain $375 long-sleeved turtlenecks, they can charge $400 for relatively simple shades and people will still spend money on them. What will they do next? Matte nude lipstick?