rly interesting game, i loved the X-Ray mechanics and choices on how to interpret the different things inside the body! my take on the story (SPOILERS):
Laynie is a Russian military experiment, made of a collage of different parts, made in a hurry because of war. Her, or rather it's body was recently made (in the past few months), possibly using a child soldier as a base for the construct considering Laynie is still in some sort of school (if I had to guess either high school or even a school for training said experiments). In a way, Laynie has deviated one way or another, since she most likely wasn't supposed to find out her true identity and purpose. The person in the radio + in the end most likely being her handler and/or creator, who has been asking for her to "come home" because they didn't want her finding out the truth. "Home" being wherever she most likely is kept, more than likely somewhere that is a secret to their government, as it's the only home she can remember and/or has left.