sure for those with experience and local knowledge. Finding trusted Thai business partners takes years. I have worked in real estate in Thailand and lived here quite a long time. Have seen a constant stream of people like this and maybe 1% of them are able to find a suitable job.
They are getting tougher on those who break the rules now and you have put yourself into that category and will come under a lot of scrutiny. Really bad idea.
No agent needed at all. Tourist visa will.be fine as.long as she has money in bank and a job or business to return to. They are looking for proof she will.return home and that she will not be working. Basically they will approve professonal working people but not bar girls.