I asked her employer for a corrected W-2. Leaving Box 1 empty is the wrong way to deal with an exemption claim on a W-4. See this link for information on getting a corrected W-2.
https://www.irs.gov/help-resources/tools-faqs/faqs-for-individuals/frequently-asked-tax-questions-an...
Also, the W-4 was submitted in 2015, which means that for 2016, in the absence of a more current W-4, the exemption lapses and the employee should have the taxes withheld as if they were single with no exceptions.
By clicking on "I did not receive a W-2 from my employer" after entering all the info for my wife I can get TurboTax to file a form 4852, which is referenced in the link above, and be able to e-file. However; I am unsure if that raises an audit risk either for myself or for the employer, so I will wait a few days to see if they will correct her W-2.
