Waiting for the right time is an odd thing for a royal couple, isn't it?
PL, remember that we are talking about the XIX century, during the Romantism times and the Victorian age, when sex was tabu.
And they were married just for 1 year and 2 months, until Estefânia died! It's enough time to have sex, but if you think they were totally strangers to each other before the marriage, you may think it is little time to know very well any person.
Usually, 2 persons met, become friends, know each other, become in love, begin dating, get engaged and then marry. With Pedro and Estefânia they first marry and then began to know each other. I think Estefânia and Pedro were still very young and innocent, they were already married but behaved like boyfriends, not man and wife, so no sex until the right time.
This is only my personal opinion.