D = Determination. The best fairytale characters I know have this trait in buckets (other suitably large utensils are available, as they say...!). They can vary from determination not to be ground down (Cinderella) to determination to survive (Hansel and Gretel). Determination can keep a character going when the world and its dog/unicorn/dragon seem to be out to "get them". Determination separates the wolf (big, bad or otherwise) from the sheep.
E = Energy. Can be topped up by determination but your characters are going to need plenty of energy to get them through whatever frightful horrors you're putting them through. Not only are there the obvious physical needs to think about, but bring in how your characters top up their mental strength. They will need plenty of that too.
F = Fairies/Fantastic Creatures. The great irony with fairytales is you can have them without fairies in (Little Red Riding Hood), but when you do use them in your stories, give them plenty to do and ensure not everything is solved with a wave of the magic wand. Your fairy character still has to work for/struggle to get success, even if that is only implied in your story. A wave of the wand may be what they do to remedy a situation or modify it (Sleeping Beauty) but there should still be issues for the characters in your story to overcome. Otherwise there is no conflict and without that, the story vanishes. Fantastic creatures can vary from animals to other magical beings (including your own invented ones) but we still need to have some sense of what they are like and where they fit in to the world you've created.
More next time...