Have you noticed your eight-year-old stealing your Vogue before you've even had a chance to look at it? Does your little boy refuse wear a shirt that doesn't have an alligator on it? Did your little girl push the $4.39 pantsuit that was such a good buy into the back of her closet and hint broadly about that $46 Cacharel gabardine jumper she saw?

If these stories sound familiar and if you spend the better part of your morning dressing your little fashion plate in an outfit that's acceptable to both you and him or her, then you're probably dealing with an early case of "clothes-mania."

No doubt sick of hearing, "Mommy, I have nothing to wear!" -- from a child who's looking right at a walk-in closet crammed full of outfits -- you trudge from store to store on Saturdays, with your fledgling clothes-horse, looking for suitable garments to add to the wardrobe.

Some of the local department stores, aware of this junior dilemma for parents of stylish children, have come up with an activity, usually held Saturday mornings, to show children some pretty clothes while interjecting some helpful advice to puzzled parents on how to deal with their prima donnas: the children's fashion show.

But take along a good sense of humor as well as your charge card.

"You just never know what to expect at a children's fashion show," says Pat Ellis, manager of the children's department at Neiman-Marcus, which will be holding its first children's presentation at its new Washington store Saturday. This particular show will feature clothing by Florence Eiseman, known especially for frill-less, classic little girls' dresses.

Though you may not notice your seven-year-old sitting around in party clothes while starting a bonfire in the back yard to burn his or her blue jeans, there is a definite trend in the children's business from denims into dressier looks. For girls there's a more feminine feeling, and many little girls are choosing dresses and skirts over former rugged duds -- a trend that's also probably true in their mothers' clothing.

"We think that children find it more comfortable to wear the cleaner look today, and what they demand most of all is comfort," says Robert Eiseman, son of Florence Eiseman and vice president of the company that bears her name, who will be at Neiman-Marcus to comment on what kids want and need in the way of fashion these days.

Eiseman, whose children's clothes retail for $20 to $70 (mostly dresses at $20 to $35), says, "We do our best not to over-design and not to overpower a child, so that the child really comes through -- not the clothes. We use mostly clear, true colors, which look best in children. Also we know by no means are jeans all over, but sales have shown us that children are returning to a preference for dressier clothes."

Taking your child to a fashion show can help to develop a sense of taste and value, and watching other children modeling the clothes may help show what styles might look best on them. But be warned, says Eiseman, who has traveled around the country doing children's shows: "Saying 'We're going to a fashion show' to a child who doesn't care about fashion can be a disaster. You probably won't get any cooperation. What we hope for is that the children and the parents who like to shop with their kids will see new possibilities."

An added treat is the spontaneity of a show that features unpredictable children as models. Every children's fashion coordinator has horror stories to tell. "At one I had a little boy walk down the runway perfectly nicely in his little outfit and I started describing all the places he could wear it," says Marjory Segal, fashion coordinator at Lord & Taylor. "Then I asked him how he liked the outfit and he screamed, 'I hate it!' and ran off stage."

A coordinator from Hecht's had another experience: "One little girl came out and put her dress over her head. The crowd loved it and they all laughed. From then on, every time she came out dressed in another outfit, she would put her dress over her head."

There are lot of other stories -- the child who won't leave the runway and just stays put until the end of the show, the junior prima donnas in the dressing room, the poor little one who has an accident on the runway -- all the commentator can do is try to play along.

Most department store shows do not use professional models -- ordinary children tend to be much more natural and unpretentious. But stage mothers should know that there are modeling agencies in town that handle children for jobs in which they can earn up to $50 per hour for photographic modeling. "Cuteness goes," says the Adair Novel agency, which suggests that interested parents send the child's photos to them at 1204 Wisconsin Ave. NW. Jeanne Ritchie of Models Ltd. (466-7372) says she is desperately looking for some twins to model, as well as children with very classic looks. There are also modeling schools for children (like Cappa Chell in Tysons Corner at 893-9500), which can teach walking posture, skin and hair care and how to pivot on a runway.

But back to the business of outfitting your child: Most children's fashion experts agree that the best way to cope with a fussy fashion plate is to select a group of clothes that you like and that are within your price range, and then let the child choose from those. As children get older, they should assume more responsibility for choosing their own clothes, because an older child is even more likely to reject things bought without consultation.

Which brings us around to the idea of a fashion show not only as entertainment, but as a learning process for the child. It can be fun for both of you, as well as a place where a newly fashion-consious dresser can get ideas of how other people his size put themselves together.

But be prepared to get some very definite feedback: Jean Cecil, mother of a five-year-old who will model in Saturday's Neiman-Marcus show, says her daughter Kate "has definite ideas about what she wants to wear, and we usually go through about three outfits every morning. When we go shopping, I try to help her select, but she usually gets her way in the end."

What's a parent to do?