I already mentioned that Discord and Twilight have 3 kids and the oldest child is their oldest and only son Paradox Epitaph, I mentioned it here
 
 
For the longest time Equestria didn’t allow gay or inter-species marriages, so Twilight had to keep her relationship whit Discord secret. She found out she was pregnant during the time she tried to debated whit the other princesses to make both of those legal, she broke down in tears as if she fails not only will people look down at her for having a child out of marriage but what about having a child who’s a hybrid.  
Thankfully her wish for gay and inter-species marriages were granted and a day after that she married Discord and at the same day gave birth to their son Paradox Epitaph.