"Love, Mary" (tonight at 9 on Channel 9) is a remarkable departure from the slew of TV movies based on real-life events -- it's not about mass murder, rape, incest, suicide or any other aberrant act guaranteed to attract high ratings. Rather, "Love, Mary" recounts the inspiring story of Mary Groda-Lewis, from her days as a rebellious teen-ager through her struggles as a middle-aged mother -- surmounting any number of obstacles on her way to becoming a doctor.

A list of the roadblocks Groda-Lewis overcame just to get from here to there would be enough to persuade anyone that next to this woman, Rocky Balboa was a quitter. Sent to reform school at the age of 13, she refused to allow dyslexia, poverty, the difficulties of raising two illegitimate children, a stroke or an interminable number of rejections from medical schools to stand in her way.

Kristy McNichol (who won two Emmys as Buddy Lawrence on the TV series "Family") plays the title character in one of her few roles since 1983, when she walked off the set of an MGM/UA movie. McNichol quietly underplays the times of triumph and humiliation in Groda-Lewis' life; even moments of awkwardly saccharine dialogue become palatable as McNichol grins sheepishly at the camera. Every scene belongs to McNichol, and it is her performance that makes "Love, Mary," for all its good intentions, more than just another tissue festival.

The movie opens with 13-year-old Mary Groda being returned to the Hollyridge Reformatory in a straitjacket after an abortive escape effort. A school administrator introduces Mary to her new guidance counselor as a "total zero" and a "garbage case." Fortunately, the counselor refuses to accept the school's diagnosis of Mary and discovers her illiteracy is a product of dyslexia.

Even more important to her survival is Mary's grim determination and uncanny ability to mix anger and empathy, humor and common sense. "God'll understand," she tells a fellow inmate who has just confessed her crime, "and if He doesn't, who needs Him, right?" By the time Mary learns to read, gets into college and wins her release from the reformatory, she leaves the inmates cheering -- "Straight As, Four Eyes. Do it for us!" And you can't help but root right along.

The movie is made up of a series of vignettes separated by months, often years. It is a credit to director Robert Day and the uniformly good cast (including Piper Laurie and Matt Clark as Mary's parents) that this potentially jarring format moves along so smoothly. In fact, the narration succeeds in chronicling an exhaustive series of events without ever becoming tedious.

At one point, Mary loads up her entire family and drives 300 miles for her 15th interview at a medical school, only to be turned down in less than five minutes. Because of her disability, she studies with an eye patch and reads at a snail's pace. She repeats classes, takes her National Boards over and over again. Her teen-age daughter runs away from home on the eve of a major exam and her father suffers a stroke in the middle of her term, prompting her to rush to his bedside.

Groda-Lewis is more than a survivor. When doctors question a diabetic child who couldn't give himself insulin injections before learning how from Mary, his explanation is simple: "All you gave me were oranges. She gave me her arm."