Senshi told a young Kitai to hide in the botanical dome so that Ursa wouldn't be able to get to him as easily. Using herself as bait, she sacrificed her life in order to hold off the Ursa and protect her younger brother.
Senshi is showed in various flashbacks. During one instance where Kitai is sleeping on a handmade water craft, Senshi appears. Kitai said that he was planning to come out of the pod, to which Senshi replied "No you didn't," with a chuckle. She claimed that Kitai did the right thing by not coming. Once Kitai started telling her that he read all the books, she raised her voice telling him to "wake up." When Kitai didn't listen, she turned her head, showing a horribly scared face, with one last plea to wake up. He finally did, realizing that he slept much longer than he should have and started off for a hot spot.
Fighting the Ursa
After having the wind knocked out of him by the Ursa, a flashback is shown of Senshi ushering a young Kitai into the pod, claiming that the Ursa won't smell him, keeping him from danger. Once again, it shows her being slammed against the wall and Kitai looking on in the pod. She died that day.