Yea, but, I think Reverend is right, you'd need to show her potential via insight/empathy/perceptive of integrity, kinda things, or else it would be "Outta nowhere" 20+ years down the line (Or as early as when it's revealed in Original Trilogy).
Problem is that the more awesome you make her, the bigger her downgrade will be once Luke and Han enter the picture. Not only will she need to be rescued, she'll be the one sitting it out while the guys take care of everything. Next movie she'll just be the love interest and the last movie she'll essentially be the victim of an ill-concieved plan which results in what she's most recognizable as. A slave in a metal bikini to a giant slug. All you'll be doing is building up potential and squashing it.
Yeah, essentially this. If she's a heroic, badass teenage Senator and Princess with developing latent Force abilities she doesn't recognize for what they are in Rebels
but then the smartass damsel in distress who relies on her bravery and a convenient blaster when Episode IV rolls around that's a bit of a downgrade and they wouldn't really feel like the same character or that she had evolved as she reached adulthood.
It just makes more logical sense within the continuity to depict her as a budding child and teenage statesman in Rebels
if you're even going to bother to show her in the new series at all, because that's what she's grown into by the time Vader seizes the Tantive IV
over Tatooine in the original film. That's the Leia we know, displaying no unusual powers and abilities and essentially just a courageous young woman who's good with subterfuge and a blaster. Let her development and use of any Force powers she has happen in the development of the OT and afterwards when it makes sense.
Besides, Star Wars fans for the most part are smart enough to know that a little girl Leia can't be running around doing things she didn't do in the Original Trilogy. They know she's the daughter of the Chosen One and the twin sister of the Great Whine Hope and that she'll come to the realization of who she really is and what her powers and potential are during ROTJ and the years after that. You don't have to make every character super-bang-pow-kewl before they're supposed to be - there are plenty of interesting stories one can tell about kid or teen Leia that don't involve latent Force powers and being Ellen Ripley with hair buns.