SOUTHERN CALIFORNIA JOB MARKET: WORK AND FAMILY : A Dearth of Mary Poppins in Today’s Nanny Market : Parenting: The search for someone to watch the children can be difficult. But there are some guidelines.

It is the sort of incident that makes parents everywhere shudder.

Returning from work one evening, Timothy McCalmont discovered 2-year-old Dylan alone in the playroom, whimpering. In the next room was his nanny, asleep on a couch. McCalmont woke the woman and fired her on the spot.

Dylan was unharmed and is now cared for by a nanny the McCalmonts consider attentive and warm. Even so, his brush with the napping nanny two years ago gnaws at McCalmont. “Who knows what might have happened if I hadn’t walked in?”

The Oakland physician is among the thousands of working parents who entrust their children to a nanny, often for 10 hours or more a day. While abusive nannies are not common, a spate of violent attacks in which children allegedly have been battered or killed is causing parents to take a closer look at who’s minding the kids.

- Last December in Thornwood, N.Y., Swiss au pair Olivia Riner was charged with dousing a 3-month-old with gasoline and setting the infant girl and the house ablaze. Riner, 20, has pleaded not guilty.

- A 19-year-old nanny, secretly videotaped beating 2-year-old Stevie Lewis of Palmdale with a wooden spoon, pleaded guilty to cruelty to children last October. Martha Mendoza was deported to Mexico after serving two months in jail.

The nonprofit International Nanny Assn. of Austin, Tex., estimates that between 75,000 and 100,000 experienced nannies are employed in U.S. homes, but, since nannies aren’t licensed, that figure is mostly conjecture. The state Department of Justice estimates that 17,000 to 20,000 unlicensed nannies or baby-sitters work in California, suggesting the nationwide figure may actually be much higher.

Once hired primarily by the wealthy, most nannies now work for middle-class families in which parents work long or unpredictable hours and require extra help at home. These nannies, mostly women between the ages of 19 and 50, cook meals for the children, wash their clothes and shuttle them to schools, parks, ballet lessons and the like.

For their efforts, the nannies--recent high school graduates, undocumented workers, displaced homemakers or the recently unemployed--receive wages that average between $175 and $250 a week in Southern California, usually with no benefits. Nanny placement agencies say wages for live-in and live-out help are roughly the same.

What parents know about the people hired to care for their children is less than what many know about a new automobile. The industry is totally unregulated, though in some states--but not California--agencies that place nannies must be licensed. Many of these agencies conduct only cursory checks into the backgrounds of people they refer for nanny positions.

“The lack of screening that goes on at some agencies is appalling,” said Lynn Peterson of Prairie Family Companions, an Oakland agency.

But it is not unheard of for an agency to do little more than exchange telephone numbers between the nanny applicant and a family, a service for which it collects fees of between $600 to $800.

Janet Shannon, president of the International Nanny Assn., said parents who decide to use an agency should ask questions about the screening process. Does it perform credit checks? Are its recruits interviewed in person or by telephone? Does it check the nanny’s driving record?

Agencies are not the only ones whose techniques are found wanting. Parents are also to blame.

Olga Reisler, an Irvine auto executive, said she knew virtually nothing about the woman she hired about five years ago to be her daughter’s first nanny. The woman, a native of Mexico, told Reisler that she had done some baby-sitting in that country, but Reisler had no way of verifying her story.

Reisler hired the woman for a year because she seemed caring and she was willing to work for only $75 a week. The woman turned out to be a godsend, but looking back, Reisler said, “I think I was lucky.”

Without hiring a detective agency, it’s difficult for most parents to check on a nanny’s background. Under a new state law, the state Department of Justice is creating a registry for baby-sitters called Trustline. Using fingerprints submitted by the nanny, the agency will check for criminal convictions and child-abuse investigations within California. When things don’t work out, though, it isn’t always the nanny’s fault. In some cases, families are inconsiderate of their nannies, even abusive. Barbara Perkins of Prestige Nanny Service in Sylmar recently removed a nanny she placed from a home because the husband harassed her.

“After she started there, he began working from home. He slipped love notes under her door; he was really coming on to her,” Perkins said.

More often, friction results from families taking their nannies for granted. Parents may consistently arrive home late, imposing on the nanny’s free time, or they may pile on household chores.

“Everyone wants Mary Poppins,” said Cindy Hines, placement director at the American Nanny School in Claremont. “Their expectations are way too high, totally unrealistic.”