2012-13 was Walsh’s first year swimming for the Sharks. Walsh earned All-Division honors in 100-yard freestyle and 100-yard backstroke. At the county championships, she was named All-Conference in the 100-yard freestyle. She was also a member of the Sharks’ 200- and 400-yard freestyle relay teams that won division and county titles and qualified for the state championships, as well as received All-Long Island accolades. The 400-freestyle relay team posted the fastest time on Long Island this year and set a new school record.