It seemed like a simple enough idea five years ago as I was checking out through the express line at Giant. Gayle was the cashier and she, like me, was due to give birth to her first child within a few weeks. Over the course of our respective pregnancies, we had established that we shared a gynecologist, basic philosophies on child-rearing and similar lifestyles. We also felt our husbands had many interests in common. A spontaneous, over-the-counter friendship blossomed.

What really sealed the friendship, however, was the dilemma of impending child care: Both of us intended to continue earning needed income after our babies were born. It's hard to say who actually came up with the idea but suddenly there it was.

"Suppose we share the kids? One day, one of us watches the children and the other works, and the next, we reverse it."

What a great idea, we both agreed. We should try it and see if it works.

Five years later, our two girls, growing up like sisters, are still best friends. Now Gayle and I are working on rearing our second children, born in June just four days apart. Although the idea of juggling child care and work schedules with one other set of parents is usually received with surprise, it has picked up among our friends and acquaintances. In fact, increasingly, we are getting asked how one goes about it.

Getting Started

Don't rush into it. Co-parenting is more than just a job, it's the basis for a family-wide friendship that comes from common goals and a similar outlook on life. Gayle and I were fortunate to have found each other before our babies were born, which was ideal, since we were able to take advantage of our newly established relationship right from the start. It may, however, take a little time for the right situation to come along.

Apart from casual contact in a place like a supermarket or in the neighborhood, other places to meet potential co-parents include parks or playgrounds, fast-food restaurants (I've met parents and their children at the local Burger King Playland), preschools, through mutual friends, church groups, Lamaze or exercise classes. Striking up a conversation with someone who is pregnant or is carrying an infant is very natural and may lead to the sort of relationship you are seeking.

What to Look For

Kid sharing would be very difficult if the parents involved don't share similar or compatible work schedules. Two parents working at home, for example; or part-time schedules outside the home. With us, there was a little of each -- Gayle worked part-time at Giant and I worked at home.

Co-parents need to be flexible. In fact, flexibility becomes one of the big advantages of child-sharing; there exists an attendant team spirit, an eagerness to make it rewarding for everyone. While it is incumbent to set up some structure that works for parents and children, the schedule is likely to vary from one week to the next, sometimes with little warning. Kids get sick; a sudden business meeting comes up; a last-minute schedule change forces a part-timer to work at an odd time of the day or evening; one week the mutual service is needed to pinch hit for an absent babysitter on a night one set of parents must go to a dinner party; another week the services are tapped to meet a deadline crunch. For it to work to its full potential, child- sharing should always be a very mobile, non-institutionalized institution.

A Few Guidelines

Sharing two kids about the same age and sex is ideal. In such a situation, the children grow up almost as siblings.

Parents of children under a year old should consider starting with half days at first. Infants are a lot of work and two of them gets tiring quickly. Also, it's easier on the kids to start slowly.

At the beginning of each week, set up the schedule for that week, even though there may be some last-minute changes as the schedule is implemented. Gayle and I usually talk to each other Sunday because she gets her week's schedule on Saturday. I like to have Tuesdays as my work day and she tries to set her schedule to accommodate that each week.

The parent who is watching the kids that day should be responsible for all child transportation. The advantage to this is that the parent with the free day truly gets a full free day, with no obligations to the children whatsoever.

The parent who is watching the children should not plan to get anything done at home that day except minding the kids.

Each set of parents should write up and sign a release form for the other set to allow emergency child care. Include Social Security numbers of parents and children, names of doctors and nearest relatives as well as permission for the co-parents to authorize medical treatment. The child's blood type, allergies and any pertinent medical information also are important.

Communicate often with your co-parent. Talk about what the kids are doing together, what they ate, how they slept, how they played. It will tell you a lot about your own child in a social situation outside his own home, information you will build on later in making decisions about schooling and play groups.

Establish right from the start what form of punishment is allowable. It is almost inevitable that each co-parent at some time will have to punish the other child.

A parent picky about his child's diet should send along special food rather than expect the co-parent to stock it.

With the exception of enough car seats to accommodate more than one child in a vehicle, no special equipment or toys are usually necessary for co-parenting. From about 15 months until age 5, kids can have a hard time sharing, so occasionally getting duplicates of a special toy may help keep fights to minimum.

Hidden Benefits

What started out for Gayle and me primarily as a marriage of convenience turned into a different approach to child-rearing. Gayle is a preschool teacher by education and avocation. We decided, as the two girls hit their third birthdays, to do a little home-schooling. She set up the curriculum and provided the materials and I watched both kids for an extra day.

The arrangement was splendid; the kids loved "mommy school," she gained an extra day of child care and I picked up tips on early childhood education.

It is for times like those that kid-sharing and co-parenting are made.