Can dependent of Tier2 ICT work in UK without primary applicant?

Hi All,
Queries on behalf of my friend. He is sponsored Tier2 ICT visa by the employer and wife has a dependent visa (2 years validity) with the below situation:
1. Wife is working on a defendant visa (2 year’s validity), if her husband is returning India in a year, would the wife be able to continue her job for rest one year ?
2. When we are working on a dependent visa, if we get a work permit, do we need cooling off period to get a work permit to work there .

thanks,
Sabana