This is what I would put her in. I was aiming for youthful/sexy/elegant. I think she should go with the "column" rather than the "flow". She has the body for it. I think she ought to emphasize her shoulders. I think a low neck line is better than a scoop or something higher which might be too "suit-of-armor". I think she will opt for the high waist which is something she seems to like and favors. I think the halter should be soft and gathered. Maybe shear over silk. The sheath below the waist could be slubbed silk or textured with shimmer. It should not be brocade which would be too heavy. This part has to be fluid and must follow and accentuate her movements. Overall, the color ought to be sapphire or cobalt or some mingling of sapphire, cobalt and teal. The jewelry ought to be delicate to counter her muscularity. Could be diamonds or marcasite. (I hope she doesn't do the big pearls). I think this tanzanite and diamond necklace from Tiffany & Co. would be fine. At the transition between the top and bottom parts of the gown, I've left the possibility for a thin blue satin cord/sash and even a space under the left bosom for one of those brooch/applique thingies she likes but she'd do better without.
I think the revelation is scheduled for Tuesday. I'm guessing she'll choose something by Maria Pinto.