I brought my elder kid to the dentist when she was 2+yo bcos of the same issue. Dentist's diagnosis then was her jaw was too small to accomodate all her milk teeth, hence the crooked teeth. I was told to bring her back at 3yo for an x-ray to confirm if she'll need braces after the permanent teeth are out cos by 3yo, the permanent teeth buds should be present in her jaw already. We didn't go back for the x-ray because her teeth straightened out before we could schedule the xray.
She is now 8yo and her millk teeth are falling out. So far, those permanent teeth that have come out are straight.