The 24-year-old captain of the Young Boys women's team died after a swimming tragedy on Saturday afternoon.
Her body was discovered at a depth of more than 200 metres in the Italian lake by an underwater robot operated from the surface.
On Saturday afternoon, "she dived into the water but never came to the surface," said the Berne club.
Ismaili made her Switzerland debut in 2014, winning 33 caps and scoring three times.
Young Boys posted an aerial photo on their web site of Ismaili's club-mates, wearing black, standing with their arms round each others shoulders and forming the shape of a heart.