Colonel Jen Kassia was Galactica's XO, stationed aboard the battlestar during the early days of the Cylon War. She was always looking out for the young Viper pilot, William Adama.
Kassia was born on a Colonial Fleet ship and grew up in a military family. She lived on the colony of New Caprica until the Cylons took her boyfriend, Callisto. The attack left her permanetly hardened.
Note
The "Battlestar Galactica" video game has its own continuity as a result of its association with the failed Original Series continuation revival in 2001.