Fire Emblem Fates, coming to the 3DS next year, will apparently be bringing back the marriage and having-children aspects that were a feature of Fire Emblem Awakening.
According to Silicon Era, once you reach S-Rank with your character, they can then get married, and unlock the option to have a child, who can then join the party.
Although Fire Emblem fates releases in the West in 2016, it will actually come out pretty soon in Japan – June 25th, 2015. Hopefully we will then get a better idea of how the game will look and play.