How many babies can a parakeet have total ???????it is a bird.?

i have two small parakeets and my lil sister does also and we want to know how mant babies the can have. she has a boy and a girl and there is a chance that they will make he a mommy and she rally wants to kow!do u have a suggestion. if u answer my questions and i are my best answer i will answer 2 of ur best questions garentied :)