Upvote:1
There is basically nothing you can do. She might not have a ban, but they can still deny nonimmigrant visas for "failure to overcome the presumption of immigrant intent" if there is anything they do not like in her history, and they do not like someone who stayed in the US, say, 1-2 years, on a visitor visa, even if their I-94 happened to be given for that long by mistake.