Mary-Kate Olsen's Shy Stripes

Mary-Kate Olsen arrives at LAX airport in Los Angeles on Saturday.

MK, 22, and sister Ashley, were seen shopping in New York City earlier in the week.

The Olsen twins recently topped the list of powerful sister acts in Hollywood according to In Touch. They were followed by Jessica and Ashlee Simpson, Jamie Lynn and Britney Spears, Beyonce and Solange Knowles and Hilary and Haylie Duff.