Looks like stain is present/ but the picture is not very clear. there can also be caries in the upper part of teeth, which can be restored now. If stains are there you can visit your dentist and get the scaling done. Stains are deposited may be due to iron content in the drinking water. Need not worry
Next Steps
visit Pedodontist for the needful
Health Tips
brush twice daily under your supervision. avoid bottle feeding at night, avoid chocolates, sugary syrups, cookies, chips, sticky foods