This part of the Guide Fallout 4 : Far Harbor is devoted to the main quest "Near Me". Now that you know everything about young Kasumi, you will decide whether she should stay in Acadia or return to her apprentices.
Related Quest: “Life Should Be Like This”
Kasumi Nakano is dead
If you attacked Acadia during the “Life Should Be Like This” quest, then Kasumi is dead (picture1). Go back to the Nakano residence and announce the news to his parents to complete the quest (picture2).
Kasumi Nakano is alive
Rewards: 508xp + Grandfather's Cache
If Kasumi survived the events of the “Life Should Be Like This” quest, go back to her and decide if she should stay in Acadia or go back to her parents (picture3). Note that this decision does not affect the quest's conclusion, even if Kasumi stays in Acadia, you will get the same reward. Anyway, then go to the Nakano residence to attend the reunion (picture4).
Satisfied, Ken Nakano will reveal the location of his father’s cache, so go to the shed behind the boathouse to find the hideout and retrieve the loot (pictures5-6).
During the reunion between Kasumi and her parents, you can tell them that their daughter is actually synthetic (picture7). From then on, you can convince them to keep it with them or let them chase it away, in both cases, the quest ends and you receive exactly the same reward (picture8).