Mary-Kate and Ashley Olsen are identical TWIN sisters who have been in the entertainment industry since they were babies. The crossword solutions for the term Mary-Kate to Ashley are SIS (3 letters), TWIN (4 letters), SISTER (6 letters), and TWINSISTER (10 letters). SIS stands for SISTER, TWIN stands for TWIN, SISTER stands for SISTER, and TWINSISTER stands for TWIN SISTER. Together, Mary-Kate and Ashley are known as the Olsen Twins and have starred in many movies and television shows.