Perhaps I,m the lucky one I had this built 9 years ago down South near to the GF,s family on land left by her mother never once did I have any issues with her family....at the time I pointed out to her that this was for her when my toes curled up and was to be used as a break from our apartment in Pattaya.....we visit monthly only staying 10/14 days which is a nice break....in the early days my GF suggested perhaps we could stay a little longer to which I replied sure you can stay here and I,ll come down again next month to see you.....did not happen of course and never been mentioned since LOL
My advice to the OP is put your foot down tell her its either your way or the highway and in my case never spend more money here that you cannot afford to walk away from if needs be.
He who pays the piper decides the tunes he plays ????