As far as I am aware her visa will be stamped as housewife- not allowed to work (lots of amusement at this for some I am sure) but I know several women on spouse visa who work in Dubai, she just needs to have approval from you that she can work and get a labour card or her company to sponsor her (it depends on the job and where she would work- free zone or otherwise)
Check your PM, have sent you further info there.
