Ignominy

Is it possible to get an extension within Thailand for a non 'O' giving a maximum stay of more than 90 days? If so what are the costs processes etc?

Thanks in advance for your help.

I will be entering Thailand in July on a Non-B visa for a permanant stay and (unless advised otherwise by your good selves) my falang girlfriend will be entering on a 60-day tourist visa (where upon she will look for work, leave Thailand and re-enter on a non-b once she has all the paper work etc).

The issue is this - neither of us will have onward tickets.  I should be OK as I will have evidence of a job/accomodation to go to, but what about her?  If she enters on a TR will immigration expect some form of onward arrangements or perhaps more importantly will she even be let on the plane in the first place?     ???

If she gets a non-b here via the route/s described on this board would that solve the problem?  What if the Non-b is turned down, does she then become PNG?

We are both UK citizens.  Thanks in advance.