Kelly Cawley, who is 2 years old but big enough to pass for 4, doesn't like it one bit when her mother, Evonne Goolagong Cawley, runs off to play tennis at a big playground called Wimbledon.

"She knows what's going on, because any time I say, 'No-o-o-o,' and makes a fuss," said Goolagong, 27."She doesn't like me leaving to play, so now I have to sort of sneak away. She's at an age where if she knows that I'm leaving she'll start crying."

Kelly may object, but just about everyone else concerned is delighted that Goolagony is back on the tennis circuit, lightning up courts with her incomparable grace and sunny disposition.

The lithe Australian, as light and nimble on her feet as Ginger Rogers, an enchantress who makes the game a joy to behold is back in the semifinals of Wimbledon, a tournament she first captivated while winning the title at 19 in 1971.

Wednesday afternoon, in the Center Court of the All England Lawn Tennis and Croquet Club, she plays her longtime rival Chris Evert, whom she first met on the same stage in a magical semifinal in 1972.

They were ascending princesses then, radiant new talents who had grown up on opposite ends of the earth: Evert in Fort Lauderdale, Fla. and Goolagong in Barellan, in the dusty sheep country of New South Wales.

By quirk of history, they grew up and made their marks in tennis without playing or even setting eyes on one another. Goolagong had already won Wimbledon, and Evert had been a semifinalist in the U.S. Open at 16, before they ever met.

Goolagong won that memorable first encounter, 4-6, 6-3, 6-4, but Evert has an 18-12 advantage in their career rivaltry, including victories in one Wimbledon (1979) and two U.S. Open (1975-76) finals. Goolagong, however, has a 4-1 edge on the grass courts that are her natural turf.

"I always enjoy matches with Evonne because our styles are so different and we never have boring matches. They're always exciting," said Evert, 24, who is also glad to have Goolagong back from the Achilles tendon injury that sidelined her for nearly a year.

"She always plays very aggressively, and I'm always counterattacking. Because she has such a good first serve and she moves so quickly. I have to go for more passing shots and more winners. I think our matches have proved to be very interesting over the years.

"I always have to concentrate twice as hard when I play Evonne, too, because sometimes she'll make a few errors and you'll think she's not in the match, but then all of a sudden she'll come back and hit four brilliant shots. So it's very difficult to beat her. She's a tough player, and she's playing pretty well now. When she gets inspired, she plays her best tennis."

If Goolagong can beat Evert she will play the winner of the other semifinal that matches defending champion Martina Navratilova against 16-yeear-old Tracy Austin for the title on Friday. If she wins, she will be the first mother to win Wimbledon since Dorothea Lambert Chambers in 1914.

"I never really thought of it that way. I wouldn't have known that if I hadn't read it in the newspapers," said Goolagong, who plans to play internationally only until Kelly is ready to go to school, or until she has a second child.

"But Wimbledon is more important to me now than it was when I won it. That year everything was so new, I had nothing to lose, and it didn't seem so important to me at that stage. It was just another big tournament. Now that tennis is more professional, and there's so much more involved in being a top player, it means more to me, I'd really like to win it again before I stop."

It wasn't long ago that Goolagong thought her career was already at a premature end. A year ago January, when she resumed play full time after a long layoff to have her baby, her left ankle became inflamed from constant jarring on hard courts.

It was hard to believe that the zephyr whose feet hardly even seemed to touch the ground when she breezed across the court could have such problems, but the strained tendon developed fluid inside and made running painful.

Goolagong kept playing because doctors told her that would strengthen the foot, but exactly a year ago she broke down with a heart-stopping scream of pain during her semifinal match against Navratilova, and limped through the final games in tears. That was her last tournament for nine months.

"The injury at Wimbledon was not the main one. I tore my calf muscle, and that healed up in a month. But the tendon problem clung on for a long while and didn't actually clear up until three or four months ago," said Goolagong.

She really did not expect to be ready for this Wimbledon physically when she entered her first tournament, the Family Circle Cup in April, at her adopted home of Hilton Head Island, S.C., and lost in the semifinals to Austin.