I dont think she can stay or get 50% she would need to go to court for the later as presently she has no contract to stay there and she is not naed on th eland registry or mortgage
give her 48 hrs to get out of dodge then change the locks and send her a letter asking her how /when she wishes to collect her stuff.
She may sue you but it is unlikely.
IIRC she needs to have made some investment such as paid for a new kitchen , conservatory type thing to have any claim as anything else would be “rent”
I bet she has not seen a lawyer so be prepared for her smug look to disappear.
if she is a mentalist or likely to act as one move a friend in as a witness in case she alleges assault or something similar
EDIT:
can I then legally start to remove her stuff from the house? What do you reckon.
better to remove her and leave the stuff in the house untouched so as not to damage it or get sued for damaging it
It is her you want out….when she is gone she will want her stuff.