Sure . She can. U need to give a No Objection NOC to her employer to change the VISA to work visa.

Has she got the offer?

All the best. I have done same with my wife too. but now she is in my Family visa. changed again.

So changing visa ither sides are no problem. Need only NOC letter. and new sponsor.

All the best. and have a good time in Doha.

If u need any formats of NOC let me know. I can give my sample letter to yoiu.