Thank you for that. You are right; it will upset my dad as he will be alarmed at her decline and likely she will alert him to where she is staying. My mum was a nurse all her life and as soon as she sees my dad, she insists on checking his catheter and starts bossing him about, which is the last thing he needs at the moment. I shudder to think what we would do if she refused to go back into the home. I just feel reassured by what you have said and feel less guilty about the necessary deception. I am learning quickly how to handle the situation with both of them, but there are a lot of times when it just feels so surreal as it is still unbelievably only ten days since this crisis hit.I would say to Mum that Dad needs to rest at the minute but once he's better and the doctor says it ok you will get them together. How they get together can be decided later on depending on circumstances.
I personally wouldn't take her to visit Dad as she may upset Dad, and other patients too and think about how you are going to get her back in to the place she's staying in if she's waiting at the door already? Promise to keep her posted etc but delay any visits for now to see Dad.
Also if she went to see him would she let the cat out the bag about where she is, and how she's not happy there? Put dad first just for now I think.