Yeah, that was based off of what they said after Elsa just used icicles to take out a heartless. Something Sora and Donald can do. Plus her walking across the river via ice is something wisdom form Sora can do to a certain degree iirc. Obviously not everything else, but we don't know if Sora and co even know that at that point in time. So calm the heck down, your waifu is safe :P.