The Future of the Mane 6 and their Friends

Princess Sunsong

"Hello Equestria!" Said Princess Sunsong, "I'm Princess Sunsong. I come from the Lost Alicorn Tribe. I'll take all your royals to meet them if you allow. We're finally ready to show ourselves again!"
Celestia, Luna, Cadance, and Twilight agree to go wish Princess Sunsong. They tell their husbands and children of their journey to meet the Lost Alicorn Tribe. They agree to watch the children. The only child that's old enough to go is princess Flurry Heart.
"Take care of our daughter," says Shining Armor as he hugs his wife and daughter goodbye.
"I will, don't you worry," Cadance replies. They head out and meet the other princesses at Canterlot where they catch the train all the way to the border of Canterlot and then they head off flying all the way to the Lost Alicorn Tribe with Sunsong as their guide.

While on the journey, Luna and Celestia ask Sunsong the one question they've held onto that hasn't been answered for them in years: "are our parents alive?"
"Yes," replies Sunsong, "your mom is anyway Celestia and Luna. Your dad died in the war. Somehow your mom managed to survive along with your sister Harmonia. They are the founders of the Lost Alicorn Tribe. Your mom is the one who sent me actually Celestia and Luna."

After hours, the princesses and Sunsong finally arrive at the Lost Alicorn Tribe. Once inside the tribe, Celestia and Luna's mom is there to greet them and is in tears when she sees her daughters. "I thought you two were dead," she said as she ran to them and hugged them.
"We thought the same about you and Harmonia too," Celestia and Luna replied as they hugged her in return. The two go off to catch up with their mom and sister. Sunsong takes the three remaining princesses to the designated meeting site. Celestia, Luna, and their family meet them there right on time.

"How'd you find us?" Harmonia inquired.
"Mother sent Sunsong for us," replied Celestia and Luna.
"But why?" Says Harmonia as she turns to her mother, "why reveal where we are?"
"Because they're family Harmonia," replies her mom, "and because it's time we reveal ourselves as the dominant race of ponies once again."
"Are you sure about that mom?" Says a concerned Celestia.
"I agree with sister," adds Luna.
"Why don't you two trust your mother?" She asks Celestia and Luna.
"Because Alicorns haven't been dominant in years, how would the locals react if we came back and took over at full force?" The sisters reply.
"I'm with Tia and Luna," adds Harmonia.
"Why are you girls turning on me? I'm your mother. I'm your mother," says their mother.
"But you're not right on this one thing mom," the sisters reply in unison. Their mom is outnumbered at this point. She has no choice but to back down. They've made an uneasy alliance and for now the rest of the Alicorns will remain hidden. Harmonia has put Sunsong on the throne in her mom's place. It's for the best interests of pony kind and that's just how they like it.