well i have enlightened her father this evening, it was a quick meeting, i did all the talking and he listened....
The issues with the car and some other issues that i didn't post up about are now sort of resolved, in so far as they wont be dragged up again.
He still believes we are being harsh on her when i said i was giving her 3 months notice and that as of 1st of Jan rent is going up to £75 per week.
I wanted to give her 1 month but my wife has asked me to compromise on this, however i am now steadfast she will be gone by 14th feb, that means we can have valentines day to ourselves

I have been told that the family will not be happy with my actions, like i really give a rats backside about that!!
I also found out that she has been telling father in law a lot of how the business is doing, he told me things that only me and my wife know.....or we thought, so my wife has hauled her over the coals tonight and she has now lost access to all the PC's in the house and the wireless network, basically she has been looking through my book on the PC, tomorrow i am having locks fitted to the office as well, although i shuld have done that for insurance reasons a long time ago.
So i didn't win the battle tonight, but the war is a different thing and that i will win