My manager/owner has now instructed me not to talk to her / say good morning / ask how she is / or talk about anything personal / mention her daughter even though my partner looks after her and she is slowly tormenting me to the point I think they want me to leave. Is there anything I can do to protect myself. This all kicked off when my manager and her eldest daughter had a huge row and she moved in with us. My manager would prefer her daughter out on the street to learn respect but I could not do this to her. Ever since work is hell, they change my time sheets and constantly watch and pressure me.
Whether or not you decide to go I personally would be looking around at other jobs. If your work is hell and this person your manager, then even if there was some kind of legal action you could take this is hardly going to improve the atmosphere. It is always easier to find a job if you already have one, so I would keep my head down and be looking at other work opportunities.
This obviously relates to your other thread about the timesheets. Contact ACAS for free independent advice (you can do it through their website) - this sounds like an attempt at constructive dismissal. It must be awful.