Assumptions: Two child family, the probability of a boy or girl is .5, sex of one child in the family is independent of the sex of the other child.

A family has at least 1 girl who was born in the AM hours of the day (i.e., sometime between midnight and noon), what is the probability that a family has 2 girls? You can assume that it is just as likely that a child is born in the AM hours of a day as the PM hours.