This is my first critique and I'm bad at spelling so give me some slack,the way you shaded and made it look like cloudsdale was far of in the distance adds a point of intrist,the background is amazing. The way you made it look like rainbow and her mother were slightly shining with white light is a nice touch. But the most interesting part is how you made rainbow's mother happy to see her child but at the same time sad she couldn't be with her all the time. All in all this is a very beautiful work of art!
I like the design, and I would like it if Rainbow Dash had a kind mother like this...but honestly, with all the evidence
1) She has abandonment issues 2) She has isolation-induced panic attacks 3) She has an unhappy childhood 4) She has rainbow hair 5) She has the constant rainbow aura of Harmony excuding from her very being 6) She released the elements of Harmony, and even overcharged Twilight's magic for life. 7) Her sonic rainboom is part of the release of the Elements of Harmony as shown when Discord got annihilated 8) She has the Greek mark of the gods as her cutie mark 9) She has insane level of physical and magical power
....its starting to look pretty obvious that Celestia is her mother.
Would it really be that effed up? One of the themes of Season 2 seemed to be trying to humanize, or simply mortalize, Celestia with mortal flaws, despite the fact of being the Goddess of Equestria. Has it occured to no one that she might have had a child in her 1000 year lifespan?
The Twilight Sparkle not chosen by destiny would of simply gotten a book for a cutie mark. That's all she was capable of manipulating before she was exposed to Rainbow Dash's excess energy from the first Sonic Rainboom, shown several times. Ponies always have the skill that their cutie mark signifies, they only gain a cutie when they recognize and accept it as their defining trait. The Element of Magic is different, its an embodyment of magical energy bestowed on Twilight, to serve as the Elements of Harmony's key, was not even close to being ready for when she was a filly. Even her adult self is not even close to the raw magical power she had when she went berserk as a child. If it was her own natural unicorn magic, no chaotic magic would have occured. TS:"Unicorn magic only happens when you decide to do it."
Alls magic is not magic, as they say. Creating whirlwinds, wind level in wings enough to send other ponies flying, magical aura trails from her flying and harnessing pure speed and energy to create a blast of immense destructive power. What ever you call it, Rainbow Dash has lots of raw power, even though it isn't unicorn magic.