Abigail is 11 years old. Her mommy doesn't love her daddy anymore. Her mommy loves Somebody Else. Somebody Else has left his wife because he loves Abigail's mommy. His name is Mr. Stenner, and when he moves in with mommy, he moves in with Abigail too.

"Me and Mr. Stenner," the CBS Afternoon Playhouse today at 4 on Channel 9, is the latest in broadcasts designed to bring sensitive issues to light for young veiwers. The story of a young girl coming to grips with her father's departure and adjusting to life with her mother's live-in lover is a novel situation for this genre, and it's been carefully and realistically done. n

The career of young April Gilpin, who plays Abigail, may benefit more from the show than viewers do, however; she is startlingly pretty and gives a convincing performance as a troubled preteen. David Ogden Stiers, as the new father, makes a welcome character departure from his role as Maj. Winchester in "M*A*S*H."

The hour is rife with lessons and hints for both parent and child and even uses the word "damn" (not usually heard in children's programs) to make a point not to curse.

Although the first half-hour is staid and conventional, as Abigail resists the new man in her mother's life, the story progresses as the girl grows in compassion and understanding. Obviously her situation is not unique in these days of marital upheavals; youngsters who find themselves in similar straits can take heart and wisdom from this intelligent treatment.