Ideal from this

A month Twilight managed to make a Garden full of the Wishing-Flower (the one from growing up is hard to do),
the mane 6 where waiting for Twilight in the Throw room,
then sedenly they were all wraped in some flower petals that come from under them
when they came out of it, they all have a horn an a pair of wings
"What in tarnashing!" A.J. yelled out while looking at the wing on her back.
"Wow, cool," Dash said before kissing A.J. on the lips, leting her horn rub on A.J's, and making A.J.'s wings to pop open

Twilight walked out with a smile on her face
she was gald and happy that her friend were all alicorns as well
she then explained her plant to them
on a "pony"'s Brithday, they can come to the castal of friendship, ask to have their wish granted, and the 6 of them would pick if it should be granted

p.s. Each Chapter would be a pony coming to them to ask for their wish to be granted

and maybe:
A.J. trying to deal with not being an earth-pony any more
See how mush more powerful they each are
Spike trying to thought of a wish for his Birth-day in 11 month, so that he can "date" Rarity
if they should make other wish's and change Equistria as they pless