Q. "Do other children get on food kicks?

"Every day for a week, my 4-year-old has wanted peanut butter on graham crackers with milk. There is no flexibility in her diet! I've been thinking of reading her Bread and Jam for Frances."

A. Actually, your 4 is just being . . . 4: controlling her life and loving every minute of it. In time she will change her preference unless you make such an issue of it that she would lose face if she gave it up.

She should, of course, be expected to eat the same family dinner as her parents (or go without), and have a breakfast that's high in protein, which doesn't mean a highly processed, sugar-added crispy-crunchy cereal. Lunch, however, is dealer's choice, and your daughter is the dealer.

Her current menu is fine, although it would be finer if she had a piece of fruit too, since vitamin C quadruples the value of any iron when it's eaten in the same meal. The peanut butter, however, is full of vitamins and graham crackers are good nutritionally. Even though they contain sugar, they probably don't contain as much as that old standby, the peanut butter and jelly sandwich.

Dear old Frances will help her stay flexible and so will some cooking of her own, for the more a child invests herself in a meal, the more she'll want to eat it.

Have your daughter help you make applesauce, for instance. Although you will offer her some at lunch (once), you don't insist if she refuses, but eat your own with many oohs and aaahs. You interest her in bread, instead of crackers, when you make bread together (with unbleached flour). You tempt her to have a tuna fish sandwich by helping her make the mayonnaise in the blender. Carrot, raisin and walnut salad is a lunch she might like--if she does the mixing--with cheese you've cut into cubes for her to poke on toothpicks. But use cheddar cheese, please, rather than the processed kind (which is only old cheddar with preservatives to keep it from spoiling and as much as 43 percent water).

Some of the cheese story, and many others, are in a new book called The Art of Feeding Children Well by Dr. Michael A. Weiner and Kathleen Goss (Warner, $6.95). Although the authors walk on the wild side sometimes, most of their information is sound, with clear explanations of how good food turns into junk food, despite the claims on the label. For a finicky eater, however, you'll want to think twice before trying some of their recipes, like vegeburgers. They might keep your little girl on peanut butter and graham crackers forever.