Honestly I'd avoid putting her in an academic preschool; it's likely to be frustrating to her if she already knows what they teach or learns it faster than they expect, and it's a waste of time that can be better spent playing with the other children.
Whether to work with her on academics at home is trickier. The argument against is that, again, there's an opportunity cost of spending time that way and you may make school fit worse. The argument for is that if you're sure she needs acceleration, and a small amount of work will make that more obvious to others, it might help.
Definitely don't see need for acceleration as a good thing to be sought! If she can learn other things than what school will teach her, at her own pace and having fun, eg violin, that's probably better.
