She can do that after the first renewal of her visa without sponsorship from an employer. Otherwise, she can apply for a work permit sponsored by an employer.
When can my wife start working as a spouse of a work permit holder of Greece?
After getting a work permit sponsored by my employer, I applied for a visa for my wife on the basis of family reunion. She entered the country three months ago and is currently unemployed. I was told that as a spouse of a work permit holder, it is possible for her to get her own work permit without sponsorship from an employer. Is this true? When can she start to apply? What requirements does she have to meet?
A general principle in the immigration code is that in the case of "family reunion," the spouse (husband or wife) has the right to work legally after the first renewal of the initial resident permit she/he has received. Besides, the first resident permit states "without a right to work," as opposed to the second permit, which states "with access to the labor market." An exception is the foreign spouse (husband or wife) of a Greek or EU citizen. She/he has the right to work from the first day she/he receives her/his temporary resident permit. This is the only acceptable option.
Definitely she could get her own work permit without sponsorship from an employer. She may start to apply anytime. She has already the Greek visa, so the most important thing is to present her occupation as self-employed.