Rin grew up in an orphanage on Cait where she led a miserable childhood. She was outcast by the other children in the orphanage for being a half-breed. After many failed escape attempts, finally at the age of 8 she managed to escape. For years she lived on the streets just getting by. When a Starfleet vessel landed on Cait, Rin, seeing her chance to get away, stowed away on board; however it was not long until she was found. Seeing how downtrodden she was, however, the commanding officer took pity on her and let her join the crew until they reached their destination of the Romulan Neutral Zone. On board, she excelled, showing ingenuity and the ability to follow orders precisely. On arriving at the Neutral Zone the commanding officer managed to get her a job on Outpost 23. Again she showed that she could make an impression quickly and after a short while was offered a transfer to Outpost 163 on Cait where she had a more senior role. Ironically, this meant she would return to the planet where she had had just escaped a miserable life.
After much deliberation, Rin decided to take the position. While working back on Cait she met Ebak Sison, who was taking part in the Caitian coming-of-age ceremony. He was then stationed on the USS Zealous and as its crew were taking shore leave on Cait, it meant that Rin was able to see more of him. After he left, despite him spending all of his shore leave on Cait where he proposed and they eventually wed, she still missed him and tried unsuccessfully many times to get a job on board the Zealous. Eventually she gave up and agreed to a transfer to the USS Dawnstar, to which Ebak transferred many years later.