Originally Posted by
Roger
I find alexb133's advice more plausible than an 'I know somebody who had a different visa' post.
A B2 visa is a non-immigrant visa, and especially in view of the OP's precautions his wife should be fine.
I agree. A visa that was never used should not be an issue. It' shard to see how changing ones mind and spending
less time in the US than planned would increase the risk of an overstay (which is what they're concerned about).