Mlawa Church record for 1924 are not available for Catholic church, only Jewish or Evangelical
There is also Polish Genealogical Forum and scans available but again not for the year you interested in
https://geneteka.genealodzy.plYou could contact Mlawa Archive so they could search it for you if you happy to cover costs of search and digital copy of the document (considering you have all names and dates correct)
Re baptism typically done same or next day sometimes within few days from birth.
During that time Napoleonic Civil Code was in force and parents were obliged to register birth within 8 days so even if parents would postpone baptism, birth had to be registered within that timeframe.
Usually childs name would be nearly at the end of the cert, sometime in addition at the top next to cert number