Ensign Maddy Calloway was a member of Starfleet and served aboard the USS Enterprise-D as a medical technician in 2370. She was romantically involved with Lieutenant junior grade Daniel Kwan before his suicide.
When questioned during the investigation of the suicide, she stated that she could think of no reason why he would kill himself. She also said that they had no problems romantically, and he was a very upbeat person. They even planned a shore leave together. (TNG: "Eye of the Beholder")