Aneesha started swimming from the year 2009 under the Veteran Swimming coach U.H.Sugath and she developed swimming without a break from 2010 and went on to be an outstanding Swimmer. She started her first event in swimming in 2009 at the Zonal Swimming Meet and secured the second place in 50 metre Freestyle event and in 2010 she secured the second place in 100 metre freestyle event as well at the same Meet. In 2011 and 2012 she came second in 100 meter freestyle event and in 2013 till the Year 2015 she secured the first place in the 100 metre Individual Freestyle swimming event and she came third in the 50 and 100 meters Breast Stroke event. In the years 2018 and 2019 she secured the First Place in 400 Meter freestyle event at the same meet continuously and she started her serious swimming in the year 2010 at the age of nine years when she won the Under 9 freestyle event and she came third in the 50 & 100 metre Breast Stroke. She participated in the Relay event too and her other team mates were Maheshika Hewage, Onthara Weerasinghe, and Devindya Jayawardena. In the 4 x 100 metre relay event her team got the first place in the freestyle event in the year 2015 and again in 2018 they won the 4 x 100 Meter freestyle relay event In the year 2019 too they won the 4 x 50 Meter freestyle relay event and apart from these victories their Relay team came second in 200 metre relay event and 3rd in 400 metre relay event in freestyle.
Aneesha participated at the Sea Swim in the two mile Sea Swimming championship continuously from the year 2014 to 2019 and followed a Life Saving Basic Course in 2017. She represented the country at the South Asian Swimming championship.