wot about , renting ur place out then renting a place with her? ur not gonna be worse off because costs u incur for rent etc ur gonna gain on ur own place , then if it does go tits up u end tennancy on the place ur rentin "together" give ur tennants relevant notice and have ur home back ,

as for her benefits , she should still get child benefit and may be able to claim some sort of help dependant on wot ur income is ,

hard as it sounds she then goes back to the situation shes in now only without u!