Working with family visa

Hi, I work at Muscat and my wife recently got one job offer from one of the companies in Muscat, but they are saying that it is hard to get work visa right now so if I have family visa, they are ready to give her job and gradually they can convert the family visa to work visa (gradually means may be months or even an year or so). is it okay? will she or me or my company sponsor face any trouble when she work with family visa?

Also in the offer letter, they are saying about 3 month probation, and the first paid leave will be after every 12 month (i.e 13th month) excluding the 3 month probation, so the first paid leave will be after 15 months from joining, and also they mentioned that if she quit before 2 year she need to serve 2 month notice period as well as to pay 750 rial.

I'm wondering whether all these are actually comes under omani labor law, even if it comes, since she is working with family visa, not work visa at least for the first few months, does this job contract (offer letter) has any standing? legally, I mean?