Looks like milk bottle caries. If she is still bottle-fed at times , make sure she doesn't fall asleep with milk in her mouth. Clean all the teeth with a wet cotton making sure her teeth are clean without any milk residue. The teeth in the picture look quite carious. A good pedodontist will take a few x rays , clinically check and give you the right opinion.

Hello, Mam After having gone through the photographs I understand that your daughter has grossly carious upper front teeth.In medical terminology she is suffering from Chronic irreversible pulpitis in upper front teeth. Investigation required-Dental X-ray with upper 4 incisors. Treatment Plan suggested will be to go in for pulpectomy followed by caps in upper 4 incisors.