If you are a Catholic with a child, then chances are very high your child has been baptised. This is usually done within a week of birth and within a month at the latest. If your child was baptised but you did not receive a certificate, then you may not know how to gain this certificate. However, by knowing the parish in which your baby was baptised, then you will be able to get a copy of her certificate.
Find the address of the parish where your child was baptised.
Write a letter to the parish priest (it is OK if you do not know his name; simply refer to the priest as "Your Reverence"). If the name of the child has changed since baptism, tell the priest the child's name and his name at the time of baptism. Also write in the letter roughly when the date of the baptism was and if the child was adopted. Finally, end the letter with a conclusion, such as "God bless" and sign your name.
Place the letter in an envelope and write your correct return address in the top left corner of the envelope. When writing the address to the Parrish, make sure you address the priest correctly. Write the correct address to the parish and place a stamp on the envelope. Eventually, you will receive a copy of your child's baptism certificate in the mail.