In the episode Call of the Cutie, after Twilight Sparkle in her still-unicorn, pre-Alicorn, pre-princess days in Ponyville, unsuccessfully tried to use her magic to prematurely grant Apple Bloom a cutie mark, she told Apple Bloom that not even magic could make cutie marks appear before their time.

Zecora the zebra also told Apple Bloom that her brand of magic (based upon alchemy and brewed potions) could not conjure up a cutie mark. See the episode The Cutie Pox.

Starlight Glimmer could use her unicorn magic to steal cutie marks from ponies, but not even Starlight could grant a young colt or filly a cutie mark using her magic .

But what about draconequus magic?

Could Discord use his non-pony magic to prematurely grant a cutie mark to a young pony?

Maybe that will be an upcoming season six episode.