My MIL has a big birthday next year and wants to go away for the weekend with us, which is lovely. But she wants to go on Thurs evening which means taking our children out of school during their gcse and a level years- the kids don’t want to plan a day or 2 off school during an important year as they don’t yet know what will be happening at that time. MIL does like to plan in advance so this makes it difficult. It also happens to be a crazy busy time for me at work after Christmas ( I’m self employed) and I can’t take time out right then unless I catch up by working at the weekends 😫. How does one tell a very demanding and strong willed MIL that we can’t just take kids out of school during important years . Husband no hope. Please help.