I was hoping for the transition to be as 'normal' as possible.
That would be nice, and aren't schools always talking about how much they care about a child's social development?
Still, half a loaf is better than none. She may find that she is so far to the top of the 1st grade bunch that a single year isn't enough. All you can do is try and see and be ready to change if needed.
Perhaps after a few weeks you can all agree to leave her in K on the books, but attend 100% of class time in 1st. But then you open yourself up to having to renegotiate next year. That's why I like the 'official skip to 2nd' and attend 1st, but you do have to be flexible, and hope for the best.
Best Wishes,
Grinity