The Lotus has Vario Grip technology, which really helps it hold an edge on ice. It would be an excellent choice, especially if your wife is already used to a stiff board. Another solid choice would be the Roxy Envi, which has magnetraction. The Rossignol Diva Mag would be a bit softer, but would also be a good all-mountain board and has magnetraction.
The Rome Blue and Arbor Push are two other freeride boards with strong reputations that would serve your wife well, although I don't believe they have special sidecuts like magetraction or vario grip to help on ice.