I made "Snap Bag" purses for my DGD's at 4 and they loved them. Maybe matching the dress.

MY 4 yo GD loves tutus made from a piece of elastic and tulle. I can make one up easily in the evening. Also loves small tote bags she can carry her treasures in

How about a fabric tic-tac-toe set? Make it so that it folds upon itself and encases the X and O's. I made the x one color and the o's a different one. My grandkids love them! 15 inch 'board', 3 inch squares.

i vote for the princess dress!

Is she crafty? When my granddaughter was about that age she loved glue, glitter, shiny things. I made her a box with bits of this and that - glue glitter, fancy ribbons, rickrack, paper doilies, packages of glass jewels, anything she could cut up and glue down. She spent many hours and a lot of glue making her masterpieces.

Fun pillowcase.
Sandy

This is a Great idea!

Maybe a pinafore type apron? Or even a quick quilt

I made my daughter a skirt out of tulle that was doubled in layer and had artificial flower petals held inside.

My granddaughters love to get nightgowns. And if she has a doll, a matching nightgown for the doll.