Good idea, my mum and I often act as a tag team - one of us goes in first then the other arrives later, then we leave in reverse order afterwards. Ask the staff to distract her when it’s time for dad to leave, and see if you can convince your dad not to say goodbye to your mum (just “pop to the loo” or slip out quietly). I know it sounds really awful but we have found that it’s a kinder way to do it, otherwise Dad would get so distressed because he couldn’t understand why he wasn’t coming with us. The staff will be really used to managing the situation, and can help you with lots of different aspects of your mum’s stay. I kept my phone on my bedside table for the first few nights but they never needed to call me, even though he wasn’t sleeping well at night, because he slept during the day instead. I really hope it all goes well for you. Keep us updated!