Q) My problem may be my 3 1/2-year-old daughter or it may be my difficulty in handling her at this age.

She is a bright, happy, sensitive little girl who clearly feels the need to assert her independence quite frequently.

She insists on dressing herself, which is fine, except when she chooses inappropriate clothing, like a summer dress when it's 40 degrees outside. She also refuses to wear anything but dresses.

It seems we lock horns constantly over the most banal things. I cook breakfast; she wants something else to eat. She will leave pots and pans all over the kitchen, after I've told her she is responsible for them, and then simply will not pick them up.

I enrolled her in a preschool program which she loved for about six weeks and the past two days has refused to go (it meets for 2 1/2 hours, three days a week). She won't say why, just that she doesn't like it any more. The first day I insisted that she go and she came back happy and excited but at the same time refusing to go back. The next day I allowed her to stay home, but I don't know if I should continue.

I am not an extremely strict mother by any means but I would like to know how much I should let her assert herself and how much I should stick to my guns. Our daily battles are wearing me out.

If it makes any difference, I have a 2 1/2-year-old boy and am expecting a third child.

A) It's always a surprise when an engaging, agreeable 3-year-old turns into a pint-sized tyrant in just six months. And they all do.

Children come apart at this age, and some even go through a period of stuttering and stumbling before they can put themselves together again, better than ever. Expect your daughter to be a rowdy delight at 4, a bit frayed at 4 1/2, and such an angel at 5 you'll be sure you did everything right.

Firm, loving discipline makes every child easier to handle at every age.

If you're too autocratic, you'll crush her independence and if you're too lax, you'll neglect her character. Either way, you'll lay the foundation for rebellion in the teen-age years.

A middle-of-the-road approach is best. Explain each rule to your child and the reason for it, and what will happen if it's not obeyed, but remember: If you don't bother to see if she does it, she won't bother to do it. When she obeys, she gets hugs and kisses, and when she doesn't, she gets a quiet, low-key reprimand and whatever discipline you promised.

You're bound to be too demanding sometimes (about three times a day) and too permissive (another three), but as long as you are fairly consistent, she'll respond to a rule in five to six days. And then you can add another -- like cleaning up the messes she makes.

When she doesn't pick up the pots, stop her from taking them out the next few times, because she "didn't know how to pick them up." And when you finally invite her to play with them in a week or so "because she's older," offer to help her put them back afterward "so she'll know where they go." She'll either let you help or she'll do it herself, and either way, they'll get back in the cupboard.

School is another example. She doesn't want to go because she has begun to wonder what she's missing at home and if she's as loved as ever -- and because she has found out something else to be independent about. You sympathize and tell her you'll miss her, and that she has to go because the other children -- naming them one by one -- need her, and the teacher expects her, or that she has left her doll there who has called to say she's lonely. She'll have something new to fret about in a few weeks.

When she dresses herself -- and she should -- expect her to wear what she pleases and for it to be different from the clothes that please you. This is a mild enough rebellion. It won't hurt your child to wear dresses -- little girls have worn them for centuries -- and it won't be as much trouble if you keep the summer dresses and party clothes out of reach.

Breakfast is handled with limited choices too -- or let her fix it herself, which will make her like it better. She's old enough to stand by you to turn the French toast in the skillet or to empty a little pitcher of berries on her cereal. Other mid-3s do better with the old "Let's eat breakfast quickly so we can get to the library for story hour." And when she dawdles on the walk, it's time to break the pace with another "Let's," as in "Let's hop on one foot" and then "walk backward" and then "march." A child thinks this is remarkably funny and you don't even want to wonder what the neighbors will think.

Basically, you're giving your child -- and yourself -- a way out.

You'll get a good grasp on the discipline issue from Who's in Control? by Susan Isaacs (Putnam; $6.95), which your local bookstore can order. High expectations help too, and so does a lighter touch. If you don't take your little girl's complaints so seriously, she won't make so many of them.

Questions may be sent to P.O. Box 15310, Washington, D.C. 20003.

Worth Noting

Dr. David Elkind, author of The Hurried Child, will speak March 9 at 8 p.m. at Francis Hammond Junior High School, 4646 Seminary Rd., Alexandria. Sponsored by the Alexandria Community Y. Admission is $5.