She will be unhappy if she makes more than you:
According to the authors of a controversial 2006 study: "American wives, even wives who hold more feminist views about working women and the division of household tasks, are typically happier when their husband earns 68% or more of the household income." Reason? "Husbands who are successful breadwinners probably give their wives the opportunity to make more choices about work and family--e.g., working part-time, staying home, or pursuing a meaningful but not particularly remunerative job." (Forbes)