Use age appropriate toothbrush and toothpaste to brush your baby's teeth. Please use just a smear of toothpaste for children under 3 years and pea sized amount for children 3 - 6 years.

Take her to see a dentist to exclude oral infections, decay, gum disease etc. If it's still persistent you may need to see a paediatrician as well to exclude other causes

You should use toothpaste with just a smear on the toothbrush for infants and pea-size for toddlers. you can use 'milk teeth' toothpaste it readily available the amount of fluoride in it has been constituted specifically for children as fluoride is very important to prevent tooth decay.

Milk teeth

It's not the brand of the toothpaste that matters but the amount of fluoride it contains. Certain imports of popular brand toothpastes might contain lower quantities of fluoride than the recommended quantity depending on the country of manufacture.
-Children ages three years and under should use toothpaste with a fluoride level of at least 1,000ppm (parts per million).
-After three years of age, children should use toothpaste with a fluoride level of 1,350-1,500ppm. Most adult toothpaste fall within this range. The level of fluoride in every toothpaste can be found on the toothpaste pack.
The recommendation is based on the optimum values of fluoride that can help prevent tooth decay."

When ur baby sprout out its first tooth