Easiest way would be to leave the basin in place. Do what Tony has said and connect into the cold feed to the basin tap.......... for DIY (you CAN do it yourself) ............. this is good, and can stay in place when she leaves........
http://www.screwfix.c...ting-tap-15mm-x/21250
Take out the WC suite ............ better still ........... take out the pan but leave the cistern in place. This all depends on how much room you have.
Put a bung in the place where the WC connects (big 4" hole) ...........
http://www.screwfix.c...plug-grey-sp296/18082
Cut the white plastic waste pipe after it leaves the basin, and put in "T" branch and one of these..............
http://www.screwfix.c...chine-trap-40mm/18640
You'll have to put a reducer between the machine trap and the "T" because your basin waste is 32mm and your trap will be 40mm...........