There comes a time in the development of many superb athletes when the years of training and practice suddenly begin to pay off, when moves that once seemed impossible and skills that seemed elusive become attainable.

In the world of women's gymnastics, that time comes earlier than in most other sports, and for Cheryl Kaneshiro, barely 12 years old, that time has come earlier than for most women gymnasts.

Ranked a Class One gymnast one year ago, Cheryl, who lives in Rockville, moved up to Elite standing last summer. Then in November, at a meet in Reno, she made the Junior Elite National Team, one of only 18 gymnasts to do so. She is the second youngest member of the squad.

"She has progressed very quickly," said Gary Anderson, coach of the Marvateens Gymnastics Club in Rockville. "It is extremely unusual. But she is determined and tough. She's got ice water in her veins. Nothing seems to phase her."

A year ago, at the annual Capitol Cup Gymnastics Competition at Montgomery College in Rockville, Cheryl drew only minimal attention from among the 150 competing gymnasts from the eastern United States and Canada. This year, she has virtually outgrown the Capitol Cup and will compete in only two of the four events at the meet, which began its preliminary round of competition yesterday.

Anderson said he decided to limit Cheryl's participation in the Capitol Cup so that her conditioning, performance and skills would peak at the international qualifying meets at the end of February.

"Those are the meets that qualify her for international competition during the summer, but its hard to peak and keep that level for 12 weeks," Anderson said. "Redoing the same routines over and over again. . . after a while, it can get boring."

At the Capitol Cup, Cheryl is competing only in the balance beam and the uneven bars, which is her favorite and best event.

"I do what's called a Deltchev," Cheryl said. "It's a man's high bar move. I swing down and then fly away with a half turn, and then I recatch the bar."

The daughter of Gail and Harry Kaneshiro (he's a computer program analyst) of Rockville, Cheryl is in the seventh grade at Parkland Junior High School and five days a week spends 4 1/2 hours at Marvateens. Like most competitive gymnasts, her career began modestly when she signed up for once-a-week, one-hour lessons a year ago.

Gradually her skills and confidence increased, and last summer she attended a gymnastics camp in Michigan owned by the former owner of Marvateens, Ruth Ann McBride.

"I'd like to keep doing this until I get to 12th grade, and maybe I can get a scholarship," Cheryl said. "I love the competition and I love traveling to the meets. It was a lot of fun at first, but now it has become frustrating when you try to do something harder and you have trouble doing it."

The finals of the Capitol Cup are scheduled for 2:30 today, with the top four gymnasts in each category competing in the uneven bars, balance beam, vault and floor execises.