The Sentry-Sparkle Kids
Yes, Twilight and Flash did get married. Within a year, they had their first foal. A few years later, their second was born, and the third a couple years after that.

*Starshine:
*Age: 16
Gender: Female

Bio:
As the oldest, Starshine feels protective of her younger siblings. As a young filly, she loved to watch her father practice fighting, always asking him to teach her whatever fighting move he was practicing. On her 10th birthday, she received a sword from him and a training manual from her mother (she got her Cutie mark after that day). For the next 2 years, Starshine read and re-read the manual, practicing every sword move to perfection.
On her 12th birthday, Twilight and Flash signed Starshine up at a junior guard school (it was just a school where foals learned tricks guards know), where she learned ground and flying sword fighting, lance fighting and throwing, advanced flying moves, martial arts, and a bunch of other pre-guard must-knows. She advanced through the levels, several levels above other fillies and colts her age.
When she turned 14, Flash and Twilight, at Starshine's request, signed their daughter up in the Royal Guard. She is in the Novice level, not a full guard yet.
She lives in between the palace in Ponyville and Guard School in Canterlot, but staying mostly in Ponyville (her mother can transport her there, and Princess Celestia or Luna transports her back (usually)).
Starshine is known for her short temper, but is always ready to help those in need (even if they annoy the hay out of her!!!!)

*Candleflame:
*Age: 9
Gender: Male

Bio:
Always the calm one in the family, Candleflame doesn't have his cutie mark yet, but that doesn't bother him…much. He joined the Cutie Mark Crusaders when he was 7, becoming the 'Guidance Councilor' of the club. He always gives excellent advice, for example: When everypony else wants to try something like rock climbing, he suggests that everypony should do what they're already good at, like painting or skiing.
Even though he loves his sister Starshine, he has a special bond with Dusk, his little sister. They romp through the giant crystal halls, ambushing each other. Starshine still does that too, but she's very busy with her training. Candleflame understands that sometimes all she wants to do is be in his company, realaxing.
Candleflame is a spectacular listener. He listens to every conversation he can, from Granny Smith telling stories, to Mayor Mare talking about repairing a building, to his mother listing off billions of scientific facts. He rarely talks, even though he's not shy, just because he loves to listen. He loves science, but isn't quite as interested in it as his mother.

Dusk:
Age: 3
Gender: Female

Bio:
Even though she can barely run, Dusk's magic is very powerful. It appears that she inherited her mother's alicorn powers. She can already do crazy magic stunts, like teleporting herself out of her crib, lifting things, and casting mild storm spells. She spends a lot of time with her mother and with Candleflame.
She loves to romp with her older brother in the large palace, creating new hiding spots with him and thinking of new games every day.